Power tools

ABSTRACT

An electrically powered hand tool is disclosed. The tool includes a motor, a power source, a work element and a controller. Various alternative features, embodiments and operative configurations are disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/581,846, which was filed on Oct. 16, 2006, issued on Feb. 12, 2008 asU.S. Pat. No. 7,328,752, which is a continuation of U.S. patentapplication Ser. No. 11/021,641, which was filed on Dec. 23, 2004,issued as U.S. Pat. No. 7,121,358 on Oct. 17, 2006, and which is acontinuation of U.S. patent application Ser. No. 10/385,215, which wasfiled on Mar. 10, 2003, issued as U.S. Pat. No. 6,834,730 on Dec. 28,2004, and which is a continuation of U.S. patent application Ser. No.09/615,388, filed Jul. 13, 2000, issuing as U.S. Pat. No. 6,536,536 onMar. 25, 2003, which is a continuation-in-part of U.S. patentapplication Ser. No. 09/302,162, filed Apr. 29, 1999 now abandoned,which is based upon and claims priority from U.S. Provisional PatentApplication Ser. No. 60/144,399, filed Jul. 16, 1999 and U.S.Provisional Patent Application Ser. No. 60/149,944, filed Aug. 19, 1999.The complete disclosures of all of the above applications are herebyincorporated by reference for all purposes.

FIELD OF THE INVENTION

The invention relates generally to hand tools, and more particularly toelectrically powered hand tools.

BACKGROUND OF THE INVENTION

Many hand tools that in the past were purely mechanical are now beingreplaced by motorized hand tools that perform the same function morequickly and with less effort by the user. Examples of conventionalelectrically powered hand tools are screwdrivers, drills, routers,sanders and a variety of saws, such as jigsaws, reciprocating saws andcircular saws.

Existing hand tools suffer from a number of deficiencies. For instance,hand tools, by their very nature are portable and thus easily stolenfrom job sites or storage areas. With battery powered tools, the weightof the tool is often excessive for comfortable extended use.Conventional electrically powered tools also do not allow the user tooptimize the tool for use with the particular user's preferences, orwith the specific requirements of a particular project or operatingcondition. For example, many tools are not adequately flexible in theiroperation to accommodate particular tasks easily and conveniently. Byway of example, drill/drivers are used to drill holes and drive screws,however, existing designs do not always accomplish these functions inthe most efficient or reliable matter. When driving screws, forinstance, it is often difficult to accurately control the depth of thescrew with existing drills. Similarly, existing drills do not providesufficient control of torque, speed and/or number of revolutions. Insome applications, the physical configuration of the drill is not wellsuited to allow access to the work sites. Various embodiments of thepresent invention address one or more of these and other deficiencies.

Many features of the present invention will become manifest to thoseversed in the art upon making reference to the detailed descriptionwhich follows and the accompanying sheets of drawings in which preferredembodiments incorporating the principles of this invention are disclosedas illustrative examples only.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view of a hand tool constructed according tothe present invention.

FIG. 2 is a fragmentary cross-sectional detail taken along the line 2-2in FIG. 1 and showing a fastening mechanism coupling the handle to thebody of the tool.

FIG. 3 is the detail of FIG. 2 showing an alternate method of providingelectrical communication between the handle and the body of the tool.

FIG. 4 is a side elevation view of another embodiment of a hand toolconstructed according to the present invention.

FIG. 5 is an elevation view of an alternate embodiment of the userinterface shown in FIGS. 1 and 4.

FIG. 6 is a side elevation view of a power supply adapted for use withthe invented hand tool.

FIG. 7 is a schematic diagram showing the communication between variouscomponents of the invented hand tool.

FIG. 8 is an isometric view of another embodiment of a hand toolconstructed according to the present invention.

FIG. 9 is a cross-sectional view of the tool of FIG. 8.

FIG. 10 is a cross-sectional view of another embodiment of the internalconstruction of the tool of FIG. 8.

FIG. 11 is an enlarged detail of the user interface of FIGS. 1 and 4-5in which a default screen is displayed.

FIG. 12 is the user interface of FIG. 11 showing a trigger screen.

FIG. 13 is a graph illustrating examples of possible ramp profiles.

FIG. 14 is the user interface of FIG. 11 showing a distance screen.

FIG. 15 is the user interface of FIG. 11 showing a sighting screen.

FIG. 16 is the user interface of FIG. 11 showing a step screen.

FIG. 17 is the user interface of FIG. 11 showing a tap screen.

FIG. 18 is the user interface of FIG. 11 showing a security screen.

FIG. 19 is a fragmentary front elevation detail showing a portion of anembodiment of the chuck and body of the hand tool of FIG. 2.

FIG. 20 is the user interface of FIG. 11 showing a push screen.

FIG. 21 illustrates various types of push profiles available.

FIG. 22 is a fragmentary detail of a portion of the body of a toolaccording to the present invention and showing a plurality of userinputs, including switches and dials that are adapted to selectivelyenable and configure operative modes and settings disclosed herein.

FIG. 23 is a fragmentary detail of a portion of a portion of the body ofa tool according to the present invention and showing a display and apair of user-inputs within a recess in the body that is selectivelyclosed with a cover.

FIG. 24 is a fragmentary side elevation view of a portion of the handleof a tool having a modular control assembly housed at leastsubstantially within the handle.

FIG. 25 is a schematic diagram showing the modular control assembly ofFIG. 24.

FIG. 26 is a schematic diagram of an embodiment of the security mode.

FIG. 27 is a side elevation view showing another embodiment of a handtool constructed according to the present invention.

FIG. 28 shows a mechanical configuration to control torque according tothe force applied by a user to a tool.

FIG. 29 is another embodiment of controlling torque by applying force toa tool.

FIG. 30 shows yet another embodiment of controlling torque by applyingforce to a tool.

FIG. 31 shows a part of the embodiment of FIG. 30.

FIG. 32 shows an embodiment that uses cams to control torque.

FIG. 33 shows a part of the embodiment of FIG. 32.

FIG. 34 shows a portion of a drill with an internally operated chuckaccording to the present invention.

FIG. 35 shows an alternative configuration of the internally operatedchuck of FIG. 34.

FIG. 36 shows an alternative chuck configuration.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS AND BEST MODE OF THEINVENTION

An electrically powered hand tool constructed according to the presentinvention is shown in FIG. 1 and generally indicated at 10. Tool 10includes a body 12 with a housing 14, a handle 16 and a plurality ofvents 18 for providing ventilation and cooling to a motor 20, which iscontained within the housing. Tool 10 further includes a work element 22in the form of a keyless chuck 28, a power source 24, a controller 26and a manual clutch, or torque control, 30. Work element 22 is adaptedto receive a bit, such as the screwdriver bit shown in FIG. 1 at 32 andis connected to a drive-train (not shown) such as is well known in theart. Examples of suitable torque control and drive-train mechanisms aredisclosed in U.S. Pat. Nos. 4,161,242, 5,440,215, 5,458,206, 5,624,000and 5,704,433, the disclosures of which are hereby incorporated byreference.

Also shown in FIG. 1 is a reversing switch 34 that selectively reversesthe direction in which the motor rotates the work element. Tool 10 alsoincludes a user input in the form of a user-input button 38, a userinterface 40 and a plurality of distance sensors 42. Controller 26controls the operation of tool 10. This includes regulating the supplyof power to motor 20, responding to signals from user inputs andsensors, and controlling the output on user interface 40. The featuresand operation of controller 26, user-input button 38, user interface 40and distance sensors 42 will be described in more detail below.

As shown, tool 10 is a battery-powered hand drill, however, it is withinthe scope of the present invention that hand tool 10 could also be inthe form of a screwdriver, right angle drill, hammer drill or otherknown types of drills and drivers. For certain aspects of the presentinvention, the tool could also be a saw, router, sander or other form ofpowered hand tool. For example, when tool 10 is a reciprocating saw,work element 22 includes an arbor with a blade; when tool 10 is arouter, work element 22 includes a collet with a router bit; when tool10 is a sander, work element 22 includes a sanding head or a pad forreceiving sandpaper; and when tool 10 is a jigsaw, work element 22includes a blade holder to receive a jigsaw blade.

As shown in FIG. 1, handle 16 extends from body 12 and terminates at abase 48 away from body 12. Handle 16 includes a trigger, or actuator, 50that is selectively depressed by a user to actuate the tool. As shown,handle 16 extends from body 12 forward of the body's rear portion 52 ina configuration known as a T-handle configuration. Other shapes andorientations of handle 16 are possible, such as a pistol gripconfiguration.

In FIG. 1, power source 24 includes a battery 54, which preferably is arechargeable battery. Battery 54 is coupled to base 48 of handle 16 byat least one (typically two) clips 56, which selectively retain thebattery in contact with handle 16. By disengaging clips 56, battery 54may be selectively removed from the tool, such as to recharge thebattery. As shown, battery 54 includes a terminal portion 58 that isinserted within a corresponding receptacle 60 within the handle todeliver electrical power to the tool.

As shown in dashed lines in FIG. 1, power source 24 may additionally, oralternatively, take the form of a power cord 62 with a plug 64 that maybe plugged into an electrical outlet to provide power to the tool.Regardless of whether power source 24 includes a battery or a power cordadapted to be inserted into an electrical socket, tool 10 is still aportable hand tool. By this it is meant that the tool is transported andsupported by hand and applied to a stationary work piece, as opposed totools, such as a table saw or drill press, which are supported by astationary base and relative to which a work piece is moved. Put anotherway, typically with a portable hand tool, as used herein, the tool isbrought to the work, rather than the work being brought to the tools.

Handle 16 may be integrally formed with or otherwise fixedly secured tohousing 14 in a mounting position in which the handle extends generallytransverse to the axis of work element 22. This is the traditionalmounting position for powered hand drills and drivers. In the embodimentshown in FIG. 1, however, the handle may also be selectively removed thehousing. For example, in FIG. 1, the handle is shown in dashed linesdetached from housing 14. In this detached configuration, the handle isgenerally indicated at 16′. For purposes of clarity, the handle will bereferred to as handle 16 when in its transverse, or traditional mountingposition, handle 16′ when in its detached mounting position, and handle16″ when in its subsequently referred to axial mounting position.Regardless of the mounting position and reference numeral, it should beunderstood that unless otherwise specified the components andsubcomponents of the handle are the same.

When the handle is selectively removable from housing 14, tool 10includes a fastening mechanism 70 that is adapted to secure the handleto the body and selectively release the handle therefrom. Examples ofsuitable fastening mechanisms include screws, threads, clips, slidelocks, snap locks, deformable fasteners, etc., provided that thefastening mechanism enables the handle to be selectively detached andreattached to housing 14. It should be understood that as used herein,the term “removable” refers to a handle that may be separated from body12 without destroying or impairing the operability of the tool. Instead,only manipulation or removal of the fastening mechanism (or selectedcomponents thereof) is required.

One example of a suitable fastening mechanism 70 is shown in FIG. 2. Asshown, handle 16 includes lips 72 and 74 that extend outwardly on eachside of the handle's upper portion 76. As shown, lips 72 and 74 divergefrom each other as they extend generally away from actuator 50 toprovide a wedge-like, or dovetail, configuration. Lips 72 and 74 arereceived within corresponding tracks 78 and 80 in the lower portion 82of body 12. Tracks 78 and 80 generally correspond to the shape of lips72 and 74. Once positioned within the tracks, a retainer 84 is manuallyor automatically positioned to at least partially obstruct the removalof lips 72 and 74, thereby preventing the unintentional removal ofhandle 16 from body 12.

As shown, retainer 84 includes a deformable member 86 that normallyprojects away from body 12 and is at least partially within a planedefined by tracks 78 and 80. As lips 72 and 74 are inserted into thetracks, member 86 is urged toward body 12 and out of the plane of thetracks, as shown in dashed lines at 86′ in FIG. 1. However, once thehandle is in its mounting position, member 86 is biased to return towardits original, unbiased position and thereby prevent removal of thehandle until a user intentionally urges the member back to its deformedposition so that the handle may be removed.

While not essential to the present invention, a tapered configuration oflips 72 and 74 assists in the secure positioning of handle 16 on body12. Once the lips are inserted within the tracks beyond a certain point,the distance between opposing portions of tracks 78 and 80 is the sameas the distance between the region of lips retained therebetween,thereby preventing the lips from being inserted any further within thetracks. The wedge-shaped, or divergent, configuration of lips 72 and 74shown in FIG. 2 is one suitable configuration. The lips may extend inother orientations as well, such as convergent and parallel to eachother. Other suitable fastening mechanisms also may be used.

A benefit of a fastening mechanism with tracks and a deformable retaineris that it does not require additional tools and does not involveremovable parts which may be lost, such as when screws or otherremovable fasteners are used. Nonetheless, such removable fasteners arestill within the scope of the invention. Another suitable fasteningmechanism is a plurality of deformable clips that are spaced around andthereby define therebetween a mounting position for the handle on body12. Any other suitable fastening mechanism may be used, and the aboveexamples are merely presented as illustrative examples of suitablefastening mechanisms.

While detached from housing 14, handle 16′ remains in electricalcommunication with the rest of tool 10 via a cable 88. Besidesmaintaining electrical communication between the power source (i.e.battery 54′) and motor 20, cable 88 also provides communication betweenthe tool's actuator 50 and controller 26. Therefore, cable 88 willgenerally include multiple wires or other suitable communication lines.For example, a pair of wires may be used to provide electrical powerbetween the battery and the rest of the tool, while typically at leastone other wire is used to provide communication between the actuator andthe controller.

Preferably cable 88 is of a sufficient length to permit a user toposition housing 14 in an operative position with one hand, while havinghandle 16′ and battery 54 supported in a spaced-relationship from body12, such as in the user's other hand. A cable of at least two feet isgenerally sufficient, with cables of between three and eight feet beingpreferred. Of course, depending upon the particular operating conditionsand a particular user's preferences, it is within the scope of theinvention that cables outside of this range may be used. When not beingused or when not fully extended from handle 16′, cable 88 may be storedwithin the handle. Alternatively, the cable may be detachable forseparate storage within the drill or elsewhere. A relatively short cablemay be used when handle 16 mounted directly to body 12 and onlyrepositioned between its traditional and axial mounting positions. Whena user desires to use the handle in its detached position, this shortercable is detached and cable 88 reattached in its place.

When handle 16 is in its standard or axial mounting position, electricalcommunication between the handle and the rest of the tool alternativelymay be established by paired contacts in the upper region 76 of thehandle and in the corresponding portion of body 12 to which the handleis mounted. An example of such a connection between the handle and bodyportions of the tool is shown in FIG. 3, in which contacts 87 engagecorresponding contacts 89 when the lips are received within the tracks.With this configuration, cable 88 would typically detachably engage thecontacts.

Because tool 10 enables a user to support the weight of battery andhandle separate from the weight of the rest of the tool, it reduces thestrain upon a user when the tool must be used for more than a short timeperiod. Anyone who has used a battery-powered drill with an 18-voltbattery for an extended period of time will appreciate the advantages ofsuch an operative configuration. Similarly, users that lack the strengthto lift and properly position a conventional battery-powered tool willfind this feature beneficial. In addition, detaching the handle andbattery also permits the work element of the tool to reach tight areasthat otherwise would be inaccessible if the handle and battery were notdetachable.

To facilitate a user maintaining a firm grip on housing 14 when the toolis used with the handle in its detached position, housing 14 may includea grippable region adapted to provide the user with a more secure graspof the housing. Additionally, the housing may be of any suitableergonomic shape to provide the user with a better grip. For example, thehousing may have a non-circular cross-sectional configuration transverseto the long axis of the housing, or it may include ergonomic recesses orprotrusions into which a user's fingers or palm may be received when thehousing is gripped. Examples of user-grippable regions and ergonomicshapes are shown in FIG. 8, which is discussed in more detailsubsequently.

Another embodiment of a hand tool constructed according to the presentinvention is shown in FIG. 4 and generally indicated at 90. Unlessotherwise indicated, tools 10 and 90 have the same components,subcomponents and possible variations, and to that effect, the samereference numerals will be used where possible. Similar to tool 10, tool90 includes a body 12 with a housing 14, handle 16, motor 20 and workelement 22. Unlike the embodiment of the tool shown in FIG. 1, tool 90does not include a manual torque control for its motor. Instead, tool 90includes electronic torque control that is regulated by controller 26responsive to user inputs and signals from sensors. It should beunderstood that a tool according to the present invention may includeboth mechanical and electronic torque control. Also, instead of thescrewdriver bit 32 shown in FIG. 1, another example of a suitable bit,namely drill bit 92, is illustrated in FIG. 4.

In FIG. 4, user interface 40 is shown mounted on the top portion 94 ofthe housing, instead of the position on the side of the housing shown inFIG. 1. It is within the scope of the position that user interface 40may be mounted in any suitable location on the tool, and the positionsshown in FIGS. 1 and 4 are merely presented to illustrate two suitablemounting positions. It is also within the scope of the present inventionthat the user interface may be separable from the body of the tool, suchas shown in FIG. 5. In FIG. 5, the user interface is generally indicatedat 40′. In this embodiment, user interface 40′ may communicate with thecontroller via a wireless signal from a transmitter/receiver 94, whichis shown in dashed lines. For example, transmitter/receiver 94 maycommunicate with the controller via infrared signals. Alternatively,user interface 40′ may communicate with the controller via a physicalcommunication line, such as a cable 96 which extends from the userinterface and includes a plug 98 that couples to an outlet 100positioned in any suitable location on the body 12 of the tool. The userinterface may even have a socket on the drill body adapted to receive aportion of the interface. A remote-computing device, such as a desktop,laptop, or hand-held computer, may also be used to transmit user inputsto controller 26. When the interface is selectively or permanentlydetached from the body of the tool, the interface may include its ownpower supply so that the interface may transmit signals to thecontroller when detached therefrom.

In FIG. 4, it can be seen that housing 14 does not include any vents.This reduces the chance of water or other contaminants entering thehousing. In fact, housing 14 is may be completely sealed so as to bewaterproof and thereby prevent water or other fluid or solidcontaminants from entering the housing. Alternatively, only theelectrical components may be waterproof so that water may enter thehousing without damaging the tool. When a water-resistant or waterproofembodiment of the tool is used, trigger 50 preferably, but notnecessarily, includes a non-mechanical pressure sensor, such as apiezoelectric, semiconductor, resistive, capacitative or inductivestrain gauge transducer or sensor, instead of a traditionalrheostat-type control. The advantage of this is that because theactuator does not include exposed moving electrical parts, it also doesnot include seams or cracks between adjacent members through which wateror other contaminants may enter and potentially damage the tool. Thus, asolid-state transducer may be more easily sealed against entry of water.Examples of suitable triggers are disclosed in U.S. Pat. No. 5,365,155,the disclosure of which is hereby incorporated by reference.

Preferably, the contacts between the battery and body of the drillshould be sealed to prevent contamination and shorting by water. Forinstance, the battery may be housed in a watertight container with onlya hole leading to the contact sockets exposed. The correspondingcontacts in the handle are insulated except for the end that is receivedin the sockets. Then, as the contacts pass through the hole leading tothe sockets, the hole is sealed and water is prevented from entering. Ofcourse, other waterproof connectors as are known in the art may also beused.

An example of such a battery connection is shown in FIG. 27 andgenerally indicated at 590. As shown, handle 16 includes a pair ofcontacts 592 that include waterproof insulation 594 extending along aportion of their length toward the body of the tool, with the tips 596of the contacts exposed. Tips 596 are received within correspondingpassages 598 on battery 54 and into electrical communication with acorresponding pair of contacts 600. As shown, passages 598 include apair of seals 602, such as rubber o-rings. The engagement of insulation594 and seals 602 prevents water or other liquids from passing throughthe passages.

When such a sealed housing is used, it is preferable that motor 20 is abrushless motor so that it will not generate the particulate and heatgenerated by conventional motors with brushes that tend to wear out overtime. For example, the motor may be a poly-phase motor, such as athree-phase motor. Of course, a poly-phase motor also may be used whenthe tool includes a vented housing. Other advantages of a three-, orpoly-phase, brushless motor over a standard motor with brushes includegreater reliability, easier electrical sealing, a wider range of power,decreased maintenance, increased efficiency, electronic reversing, nosparking (which can be important in environments in which potentiallyexplosive gasses are present), less required gearing to reach a low rpm,and a wider rpm range. It should be understood that these advantages arepresented to identify, in a non-limiting manner, advantages of onepossible motor over the standard motor used in electrically powered handtools. However, both of these and other types of motors may be usedwithin the scope of the present invention, and it is possible that noteach of the advantages are realized with a particular embodiment of sucha motor.

A variation of cable 88 is shown in FIG. 4 and generally indicated at102. Cable 102 enables battery 54 to be detached from the tool, whilestill remaining in electrical communication therewith. In operation,cable 102 functions much like an extension cord, in that it enablesbattery 54 to be positioned apart from body 12, while retaining theelectrical communication therebetween. By having the weight of thebattery separate from the weight of the rest of the tool, the batterymay be supported or otherwise positioned in an out-of-the-way position,while the rest of the tool is operated by the user. For example, thebattery may be clipped to the user's belt, placed in the user's pocket,or supported on the ground or other adjacent surface, instead of havingto be supported along with the rest of the tool. For example, a clip forattaching the battery to the user's belt, pants, tool belt or othersuitable garment is indicated generally at 103. As described above inthe context of the detachable handle, reducing the weight of theoperative portion of the tool is advantageous. In addition, by mountingthe battery away from the tool, a larger battery can be accommodatedwithout increasing the weight of the tool unacceptably.

Cable 102 includes a pair of ends 104 and 106. End 104 includes aterminal portion 108, much like terminal portion 58, which is sized tobe received within receptacle 60 of handle 16 and to transmit electricalpower thereto. As shown, end 104 further includes a cover plate 110 withone or more receivers 112 that are selectively engaged by clips 56 toretain the cover plate against the base 48 of handle 16. The other end106 includes a receptacle 114 that is sized to removably receive theterminal portion of the battery. As shown, end 106 further includes acover plate 115 that selectively couples to battery 54, such as withclip 117. When both ends 104 and 106 are coupled respectively to thereceptacle and terminal portion, the battery is in electricalcommunication with the motor and other components of the tool.

In a further variation of this embodiment, tool 90 may be selectivelyadapted to be powered by either a battery or an electrical outlet. Toadapt tool 90 to receive power from an electrical outlet, tool 90 may beselectively coupled to a power supply, such as shown in FIG. 6. Supply118 includes a terminal 120 sized to be selectively coupled to end 106of cable 102 or receptacle 60 of handle 16. Supply 118 further includesa transformer 122 that is adapted to convert power from an electricaloutlet to the voltage and current normally received from battery 54.Alternatively, the tool can be provided with internal or attachablecircuitry to step-down the line voltage to a standard battery voltage.Supply 118 further includes a conventional electrical plug 124 thatprovides power to tool 90 when inserted into an electrical outlet. Othersuitable forms of plugs and electrical connections may be used toconnect supply 118 with the tool.

In FIG. 4, an alternative mounting position for handle 16 is shown.Instead of the traditional, or standard, mounting position in which thehandle extends generally transverse to the long axis 116 of body 12, asshown in FIG. 1, the handle may selectively extend generally along theaxis, as shown in FIG. 4. In this axial mounting position, the handle isgenerally indicated at 16″, and it extends rearwardly from the rearportion 52 of body 12. To secure the handle to this axial mountingposition, tool 90 includes a similar fastening mechanism 70 proximateits rear portion 52. For example, as shown in FIG. 4, portion 52includes a pair of tracks 126 and 128, which define a slot into whichlips 72 and 74 of the handle may be selectively inserted.

It should be understood that the passages, or slots, defined by tracks126 and 128 and tracks 78 and 80 both should be sized to permit the lipsof the handle to be inserted and selectively retained therein. By thisit is meant that the rear portion 52 of the body will generally includethe same shape and configuration of tracks, deformable clips, terminalsor other sockets, etc. as used on the lower portion of the body.Therefore, the handle can be selectively positioned between either thetransverse mounting position shown in FIG. 1 at 16, a detached position,such as shown in FIG. 1 at 16′, or the axial mounting position shown inFIG. 4 at 16″.

It should be understood that portions of the fastening mechanism mayhave different sizes and shapes selected because of the differences insize of rear portion 52 compared to lower portion 82. For example, aretainer for the axial mounting position is generally indicated at 84′and in this embodiment includes a spring-loaded slide 129. From thestarting position shown in solid lines in FIG. 4, a user may selectivelyurge the slide in the direction of work element 22, such as to theposition indicated in dashed lines at 129′. In this position, slide 129is removed from obstructing the path of lips 72 and 74 into thecorresponding tracks of rear portion 52. Once the handle is insertedinto its axial mounting position, the user releases the slide, and itreturns to its starting position, thereby preventing the unintentionalremoval of the handle. Other suitable manual and biased retainers may beused and are within the scope of the present invention.

As shown in FIG. 4, rear portion 52 is inclined relative to long axis116 so that handle 16″ extends generally along the axis when the handleis in its axial mounting position. It is within the scope of the presentinvention that other shapes for handle 16 and rear portion 52 may beused. For example, the end portion may extend transverse to the longaxis so that the handle extends at an angle with respect to axis 116.Similarly, it is also possible that the handle may be oriented so thatit would extend generally along axis 116 when rear portion 52 has such atransverse orientation. Other shapes and configurations are alsopossible, such as a hinged handle that selectively pivots or slides toany of a range of positions between the traditional and axial positions.

For example, a single pair of arcuate tracks may extend between andincluding the positions of the tracks shown in FIGS. 1 and 4. Lips 72and 74 may be similarly curved to correspond to the shape of the tracksand thereby be selectively positioned in the traditional or axialposition, as well as anywhere therebetween along the arcuate path of thetracks. In such a configuration, the rear portion of the housing shouldbe shaped so that it does not obstruct the slidable movement of thehandle along this curved path.

Turning now to FIG. 7, a representative block diagram of the componentsof drills 10 and 90 is shown. In the diagram, it can be seen thatcontroller 26 receives inputs from distance sensors 42, power source 24,and user inputs 36 (including reversing switch 34, button 38, actuator50, and the subsequently described user interface controls). Controller26 also receives inputs from a variety of other internal and externalsensors, which are represented as a group in FIG. 7 with referencenumeral 125. These sensors may include sensors to detect the speed ofrotation of the chuck, the relative rotational position of the chuckwith respect to the body of the tool, the position of the trigger alongits possible range of positions, the torque exerted on the work element,the life of the battery, the amount of energy drawn from the battery andthe rate at which such energy is being drawn, and the axial pressurebeing applied to the work element, among others. It should be understoodthat none of these sensors are essential to all embodiments of theinvention, and that a particular embodiment may include none, some, orall of these sensors. Other conventional sensors used in electricallypowered hand tools, such as temperature sensors to prevent overheating,may be included as well.

Controller 26 controls the operation of the tool. This includesregulating the supply of power to motor 20, responding to signals fromuser inputs and sensors, and controlling the display on user interface40. Controller 26 regulates the amount of power delivered to motor 20responsive to the inputs from the sensors and user inputs, therebycontrolling the torque and rotation of the work element. Controller 26typically includes a microprocessor or microcontroller with associatedmemory for data and instructions to control the operation of the motorand user interface. Preferably, this memory includes at least anon-volatile component so that stored values are not lost when thetool's power source (i.e. battery or connection to an electrical outlet)is disconnected. Furthermore, the memory and programming stored thereinpreferably may be selectively upgraded from a remote source, such as anyof the computing devices described herein. One advantage of providing anupgradeable programming for the controller is that new functions can beadded as they are developed without requiring replacement of the entiredevice. To this end, it is preferable, although certainly not essential,that the user interface display be of the bit-mapped type, rather thanicon based so that greater freedom is provided in changing theappearance of the display with updated programming.

Although a microcontroller is preferred because of the flexibilityprovided thereby, it should be understood that the various features andfunctions described herein could also be implemented with a controllerutilizing analog circuitry.

The controller monitors signals from the various user inputs and sensorsto control the operation of the tool. As will be understood by those ofskill in the art, the controller will typically control the speed andtorque of the motor by regulating power to the motor using one or moreMOSFET transistors or TRIAC devices. Either type of device can beoperated with logic level signals, such as output from a microcontrollerand MOSFETs are capable of rapidly switching the high currents sometimesutilized in battery powered tools.

With most variable speed tools, the controller regulates power to themotor by sending short pulses of full power to the motor. The pulsestypically have a frequency between several hundred and tens of thousandsof hertz. By varying the duty cycle of the pulses, i.e. the ratio of theon to off time, the controller can control how much power is deliveredto the motor. By monitoring the rotation of the motor or chuck, thecontroller can send more power if the chuck slows below the desiredspeed or reduce the power if the chuck is rotating to fast. Thus, inmodern variable speed tools, battery-powered or corded, the trigger isnormally used to select a desired speed, and the controller makeswhatever power adjustments are necessary to achieve that speed withinthe range of available power and limited by feedback rates. In general,for purposes of the embodiments of the present invention which utilizespeed or torque control, any known speed control system which canregulate motor speed and/or torque can be used. See, for example, U.S.Pat. Nos. 4,307,325, 4,317,176, 4,412,158, 4,503,370, 5,563,482,5,754,019, and 5,798,584, which are incorporated herein by reference,for disclosures of speed and torque controls for use in power tools.

Little additional circuit complexity is required for control of apoly-phase motor beyond that required for variable speed control of DCor AC motors. In particular, as is well understood in the art ofpoly-phase motors and controllers, by sequentially pulsing power to thewindings, the armature can be made to rotate. The armature can rely oninduced magnetic fields or can utilize a permanent magnet. Just as withDC motor control, the torque of the motor at a given speed can beregulated by regulating the duty cycle of the pulses to the windings.Similarly, changing the sequential rate at which the windings areenergized can control the speed of rotation. One example of a suitablepoly-phase motor for use in certain embodiments of the present inventionis sold by Model Electronics Corp. of Seattle, Wash. as the MEC Turbo10/20 Brushless motor. See also U.S. Pat. No. 5,619,085, which isincorporated herein by reference, for additional details and backgroundon the design and control of small poly-phase motors.

As mentioned above, poly-phase motors offer certain advantages in someapplications. For instance, because poly-phase motors do not includebrushes, it is quite simple to seal the electrical components of suchmotors against shorting by water. In fact, such motors can operatenormally with the armature completely submerged as long as all of theelectrical wiring is insulated to prevent water from reaching theconductors. Furthermore, because the rotational direction can bereversed by changing the sequence in which the windings are energized,there is no need for a mechanical switch to reverse the motor, as isused in most battery-powered drills. Typical DC reversing switches usedin battery operated drills are double-pole double-throw devices. Theseswitches have twelve contacts and are therefore relatively complex andexpensive. They are also subject to failure in any one of the contacts.With a poly-phase motor, only a single contact momentary switch isneeded to signal the controller to reverse the motor. This solid-statereversing capability of a poly-phase motor is also useful in thehereinafter described tap and chuck lock modes, for instance, where itis desirable to reverse the motor without direct input from the user.Also, this makes sealing the electronics against water much simpler.

The armature of a poly-phase motor does not require any directelectrical connection to the remainder of the motor. In fact, thearmature may simply consist of permanent magnets. Even if an armaturewith induction windings is used, it is a simple matter to dip thearmature in an insulating varnish or other coating to prevent shortingby water. The fixed winding on the housing of the motor are likewiseisolated by coating with an insulating material. Such dipping can becompleted after assembly so that any wire joints are similarlyinsulated. The absence of brushes also makes a poly-phase motorpreferable in potentially explosive environments because of theelimination of sparking that occurs at such brushes. Thus, drill 90shown in FIG. 4 and equipped with a poly-phase motor and relativelysimple shielding of electrical components can readily be operated in awet environment or even underwater.

Another embodiment of a tool constructed according to the presentinvention is shown in FIG. 8 and indicated generally at 130. Tool 130differs from tools 10 and 90 in that it has a much smaller housing 132that is sized to be held in a user's palm. As shown, housing 132 has agenerally cylindrical or disk-like configuration, with a front portion134, a rear portion 136, and an edge region 138 extending between theperimeters of the front and rear portions. As shown, edge region 138includes a contact surface, which preferably is adapted to provide forsecure gripping by a user. For example, the surface may be formed of atactile, non-slick surface so that the user may easily grasp the tooland maintain the user's grip while the tool is operated and subjected totorque. As such, it may also be referred to as a user-grippable surface.

As shown, tool 130 also includes a plurality of ergonomic protrusions142 that define wells, or recesses, 144 into which the user's fingersmay be seated to provide a firmer grip and increased resistance toinadvertent rotation. As shown in FIG. 8, protrusions 142 radiateoutward from edge region 138 to define finger recesses 144. However, itis within the scope of the invention that the recesses may extendinwardly from edge region 138. Other configurations for housing 132 maybe used, including cylindrical and other geometrically and ergonomicallyshaped housings.

Also shown in FIG. 8 are a power supply 24 (in this case a power cord146 with a plug 148), the previously described distance sensors 42, anda portion of the tool's work element 22, including a keyless chuck 150.Instead of power cord 146, tool 130 may also be powered by a battery,which may be directly coupled to the housing of tool 130. To reduce thesize and weight of tool 130 that must be supported by the user in onehand, the battery may be electronically coupled to the tool by a powercord, such as described previously. For example, in place of plug 148,cord 146 may include a receptacle adapted to receive the terminalportion of a battery.

Tool 130 further includes an actuator (which in this embodiment is apush button 152), a reversing switch 153, and a manual chuck hold 154.Tool 130 optionally may include an input port 156 for the embodiment ofthe user interface shown in FIG. 6. Alternatively, the tool 130 may notinclude the user interface, may include the user interface mounted onhousing 130, such as on rear portion 136, or may include a userinterface that communicates with the controller via wirelesscommunication, as also shown and described with respect to FIG. 6.

In FIG. 9, one possible internal construction for drill 130 is shown.Besides the previously described housing 132, work element 22 and powersource 24, drill 130 includes a motor 158. Motor 158 includes fieldwindings 160 and an armature 162. For purposes of simplifying thedrawings, wiring and other conventional sensors are not shown in FIGS. 8and 9. It should be understood that conventional wiring and internalsensors and controls are also contained within shell 132, as is known inthe art. The same applies to the previously described embodimentsaccording to the present invention.

In the embodiment illustrated in FIG. 9, the armature surrounds thechuck, and they are joined to rotate as a unit. Bearings 164 roll inraces 166 and 168 formed on opposed faces of the armature and fieldwindings. Similar to the previously described embodiments, the armatureand windings can be of the DC, AC/DC or poly-phase type. Although it isnot essential that the winding and/or armature surround the chuck, thegreater diameter of the windings and armature increases the availabletorque relative to a smaller diameter motor. Preferably, motor 158 is abrushless motor that does not require external venting, and theelectrical components are sealed against entry of water to permitoperation of the tool in wet environments.

Chuck hold 154 allows the user to hold a shell 155 of the chuckstationary while operating the motor to tighten or loosen the chuck on abit (not shown). By pressing the chuck hold, a rod 172 is pushed intoone of multiple lock holes 174 formed in the shell of the chuck. Oncethe chuck is sufficiently loosened or tightened, such as to respectivelyallow insertion or removal of a bit, the chuck hold is released and rod172 is withdrawn from the lock hole within which it was inserted. Asshown in FIG. 9, a spring 175 is biased to automatically withdraw rod172 from the lock holes when a user stops pressing on chuck hold 154.

An auxiliary armature access hole 176 is provided to allow manuallocking and unlocking of the chuck via an access hole on rear portion136. In particular, by inserting a nail or similar member in the accesshole, the base 180 of the chuck can be prevented from rotating and theuser can turn the shell of the chuck manually. Alternatively, a pushbutton mechanism with a pin or rod, such as that shown with respect tochuck hold 154, may be used in place of the access hole and insertedmember. In either embodiment, depressing the button or inserting a nailor other member into hole 176 causes the pin or inserted member toengage a receptacle 178 formed in the base 180 of chuck 150.

Another illustrative example of a suitable internal construction of tool130 is shown in FIG. 10. In FIG. 10, tool 130 not only includes bearings164 which roll in races 166 and 168 formed on opposed faces of armature162 and field windings 160, but also includes bearings 190 which roll inraces 192 and 194 formed in opposed faces of armature 162 and base 180.In this configuration, field windings 160, armature 162 and base 180 ofchuck 150 all are rotatable relative to each other. Field windings 160are fixed relative to housing 132, such as being secured to the inneredge 196 of the housing (as shown in FIG. 10) or otherwise mountedwithin the housing.

In FIG. 10, tool 130 includes a gear system, which is generallyindicated at 198 and which is adapted to reduce the speed at which thechuck rotates relative to the speed of rotation of the armature. Gearsystem 198 includes a ring gear 200 that is mounted on the armature 162and extends beneath chuck 150. Although armature 162 may include gapsbetween adjacent segments, ring gear 200 forms a complete circle withinthe housing. Gear system 198 further includes a fixed gear 202 that isnon-rotatably mounted on the lower surface of the housing. As shown,fixed gear 202 is in the form of a sun gear, however, it may also be aring gear or other suitable structure.

Ring gear 200 and fixed gear 202 respectively include teeth 204 and 206that are engaged by corresponding teeth 208 and 210 on at least oneplanetary gear 212. Although only one planetary gear 212 is shown in thesectional view of FIG. 10, it should be understood that it is preferablethat at least two or three equally spaced-apart gears are used tominimize the asymmetric torque created by the rotation of the gearsabout fixed gear 202. Each planetary gear 212 includes a drive gear 214and a pinion gear 216. Each planetary gear is rotatably supported on anaxis 218 secured to the chuck.

As armature 162 rotates, ring gear 200 drives the rotation of theplanetary gears. The planetary gears are then driven to orbit the fixedgear by spin imparted from the ring gear. Because the planetary gearsare mounted to the chuck, the chuck rotates with the orbit of theplanetary gears. This configuration provides a substantial reduction inthe rotation speed of the chuck and corresponding increase in torque.The speed can be controlled by selecting the size of the drive, pinionand sun gears, relative to each other and the ring gear. It will ofcourse be understood that many other gear arrangements could alsoproduce suitable speed reduction, and that the configuration shown inFIG. 10 is shown to illustrate one suitable embodiment.

Located between the back of the chuck and the front of the sun gear inFIG. 10 are a thrust bearing 217 and a force transducer 219. Similarly,in FIG. 9, thrust bearing 217 and force transducer 219 are shownextending between the base of the chuck and the lower surface of housing132. Thrust bearing 217 bears the axial load created during operation ofthe tool, and force transducer 219 is used to monitor the amount offorce or pressure being applied to the tool. As previously described inthe context of a trigger, any of numerous different types offorce-sensing devices may be used for transducer 219. The output of thetransducer is fed to the controller to be used in regulating torque insome modes, as is described below. Alternatively, the force sensingtransducer could be applied as a layer to the back of the housing asshown in FIG. 9 to directly sense the pressure applied to the drill. Ofcourse, similar force transducers could be utilized in connection withthe other embodiments described with modifications appropriate to theparticular application, to enable the below-described push modefunctionality.

In FIG. 11, user interface 40 is shown in more detail. Interface 40includes a display 220 and a plurality of user input controls, which aregenerally indicated at 222. As shown, the controls include a pluralityof push buttons 224, 226 and 228, as well as a microphone/speaker 229.Buttons 224-228 enable a user to toggle between the screens and modesdisplayable on display 220, and to select and input values for any ofthe available options, as discussed in more detail subsequently. In theembodiment shown, buttons 224-228 respectively include up arrow, downarrow and enter buttons, however, it is within the scope of theinvention that other configurations and numbers of buttons may be used.Similarly, other forms of user input controls may be used, such asslides, track balls, switches, and pointing devices. Of course, althoughthe described user interface is relatively large and complex, it is alsopossible to provide a much smaller user interface which less informationdisplayed at a time.

Trigger 50 may also be used to provide user inputs, as can chuck 150.Both trigger 50 and chuck 150 can be provided with associated internalsensors to determine the relative position of the trigger and chuck. Thesignals from these sensors may also be used to selectively scrollthrough a range of possible values or to establish selected readings. Anadvantage of chuck 150 as a user-input device is that it is rotatableboth clockwise and counterclockwise without having a limited range ofpositions like the trigger which only travels in a range between definedend points. The user-input controls may also include an on/off buttonthat selectively disables display 220 and/or buttons 224-228.

FIG. 11 illustrates a default, or home, screen 230 of display 220. Thisis the screen that is most often displayed to a user, and to which thecontroller defaults after user inputs are completed on any of thesubsequently described screens. As shown, screen 230 includes a batteryregion 232, a settings region 234 and a feedback region 236.

Battery region 232 provides a user with information about the status ofbattery 54. As shown, region 232 displays at 238 the percentage oftheoretical battery life remaining, and at 240 the energy (typicallymeasured in amp-hours) output by the battery since installed. Either ofthese readings may be displayed independent of the other, and othertextual or symbolic representations may be used. For example, the iconof a battery with incremental bar-graph-like readings may be used torepresent the theoretical amount of battery life remaining, and a numbermay be understood to represent the amount of work performed.

This feature is useful to allow a user to monitor the status of thebattery during use. In particular, a user would want to check theremaining battery capacity before starting a project that may requiremore battery reserve than currently available. This is especially trueif the task is carried out on a ladder or other location where changingthe battery might prove difficult. By comparing the battery outputactually used with the theoretical or historical capacity of theparticular battery pack, a user is able to determine whether aparticular battery pack is performing up to expectations. The batteryoutput is monitored, for example, by sensing the current from thebattery via a current sensor (not shown). The integral of that signalover time corresponds to the total current output of the pack, while theinstantaneous signal can also be displayed to indicate the real-timeload on the battery.

Settings region 234 displays information to the user about the currentsetup of programmed and user-selected modes for the tool. As shown inFIG. 11, region 234 includes at least one mode 242 and its (their)corresponding value(s) 244. For example, as shown in FIG. 11, nineoperational modes are shown, each of which has at least one value. Thenine illustrated modes are trigger 246, distance 248, sighting 250, step252, tap 254, security 256, chuck hold 258, voice 260 and push 262, eachof which has at least one corresponding value and may trigger thedisplay of one or more additional screens, as described in more detailsubsequently. It should be understood that icons may be used in place ofor in conjunction with the textual names for the modes.

Values 244 are stored in the memory of controller 26. Responsive to theuser-selected and/or predetermined values, controller regulates andadjusts the interaction of actuator 50, power source 24, motor 20, workunit 22, as well as the sensors and user-inputs. For example, bypressing enter button 228, the first displayed mode, namely, triggermode 246 is highlighted or otherwise indicated to be the temporarilyselected mode. By pressing the enter button again, trigger mode isselected, thereby either enabling the user to directly adjust thecorresponding value, or replacing default screen 230 with one or moreadditional screens through which the selected mode is configured anduser-inputs are inputted.

Alternatively, instead of pressing the enter button again to select thecurrently highlighted mode, arrow buttons 224 and 226 may be used toscroll through the available modes. When the desired mode is temporarilyselected, enter button 228 can then be pressed to adjust theconfiguration of that mode. In addition to, or in place of, the use ofthe arrow and enter buttons to select modes, trigger 50, chuck 28 anduser-input button 38 may be used. For example, the rotation of the chuckmay be used to scroll between available modes or settings, while thetrigger is used to select an indicated mode or setting. In thisconfiguration, a user-input button, such as button 38 or enter button226 typically is initially pressed to indicate to the controller thatthe chuck and trigger are temporarily to be used to configure the userinterface instead of being used to operate the tool.

Turning to the details of trigger mode 246, it enables a user toselectively use trigger 50 to control the speed of rotation of thechuck, or alternatively to control the torque exerted by the chuck. Whentrigger mode 246 is selected, default screen 230 is replaced withtrigger screen 264, which contains its own sequence of settings 266 andcorresponding values 268. As shown in FIG. 12, trigger screen 264includes multiple settings, including a setting 270 in which the usertoggles between the trigger controlling the torque or the speed of thework element. As a reminder to the user when user interface 40 returnsto its default screen 230, the selected value for setting 270 is alsoshown on default screen as either a “T” (trigger) or a “S” (speed).

When the speed of rotation option is selected, the tool functions muchlike a conventional drill, in that actuation of trigger 50 controls thespeed of rotation of the work element. Therefore, when the trigger isnot actuated, the work element is in its resting, non-rotating position.As the trigger is actuated, work element 22 begins to spin, and the rateof rotation of the work element continues to increase to a maximum speedof rotation when the trigger is fully actuated.

On the other hand, when the torque option is selected, actuation oftrigger 50 controls the torque exerted by the work element. Because thisoption enables the user to positively control the force exerted, itreduces the likelihood of stripping a screw or driving a screw through awork piece because too much force is inadvertently applied. Instead, theuser can select and apply only the required amount of force, or torque.An example of when this torque control is desirable is when the tool isused to drill or screw into a series of work pieces of varying orundetermined density. Where one amount of torque may be preferred for aparticular density of work piece, another torque may be preferred asthat density changes.

As trigger 50 is actuated from its resting position, the applied torqueat the chuck is increased from zero. Once the applied torque exceeds theforce necessary to start chuck 28 rotating, such as to turn a screw, thechuck begins to rotate up to a defined maximum speed. Regardless of thespeed of rotation, however, the applied torque remains controlled bytrigger 50. Therefore, once chuck 50 is rotating, further actuating thetrigger will increase the available applied torque without directlyincreasing the speed of rotation. The speed of rotation will beestablished at a defined maximum value. Sometimes, this maximum speedwill not be obtained because insufficient torque is being applied.Therefore, as the applied torque is increased, the speed may beincreased indirectly because the maximum value is now completely, ormore closely, attained.

Rather than abruptly increasing to the maximum speed as soon as theapplied torque exceeds the torque required to start the chuck rotating,a gradual feedback is preferably incorporated. Therefore, if the appliedtorque exceeds the required torque only slightly, the speed at which thechuck rotates will remain relatively low. As the trigger is furtherdepressed and the spread between the applied torque and the requiredtorque increases, so will the speed. This feedback gain prevents abruptspeed changes and allows the user to control the speed even in torquemode. A value 303 of a gain coefficient 301 between the torquedifferential and the speed can be selectively adjusted by the user toprovide a desired response.

From trigger mode 246, the user also may selectively control the maximumspeed of rotation and the maximum applied torque. As shown in FIG. 12,these options are controlled via settings 272 and 274. Both respectivelygive a user control over options that previously could at best only bechosen from a few discrete, pre-established values. For example, in FIG.12, speed setting 272 has a corresponding value 276 of 1600 rpm. Value276 may be inputted via any of the previously described user inputs. Forexample, the user's selected maximum speed of rotation for a particularproject may be inputted by scrolling through a menu of available speedswith push buttons or rotation of the chuck, or by inputting a selectedvalue digit by digit. Instead of the relatively high speed shown in FIG.12, it should be understood that a relatively low maximum speed may beentered as well. A low maximum speed enables the user to have much morecontrol over the relative speed of the work element within this nownarrower range of speeds, relative to the same range of positions of thetrigger.

In FIG. 12, it may also be seen that maximum torque setting 274 has itsown corresponding value 278, through which the user selectively controlsthe maximum torque applied to the work element. It should be understoodthat settings 272 and 274 have the synergistic effect of enabling theuser to have full control over both the maximum applied torque and themaximum speed at which the chuck will rotate, with either of thesesettings being selectively controlled during operation via trigger 50responsive to setting 270. The settings essentially enable the user tooptimize the tool on a case-by-case basis to selectively utilize adiscrete, user-selected subset of the maximum ranges of speed and/ortorque available.

Besides selectively controlling the maximum speed of rotation andmaximum applied torque, trigger mode 246 also enables the user to selectthe profile through which the speed or torque (depending on the selectedconfiguration of setting 270) is ramped up and down responsive to therelative position of the trigger. The profile is selected via setting280 and includes a corresponding user-selected value 282. Value 282 maybe selected between a range of values centered about a standard, orlinear relationship between the resting and fully actuated triggerpositions with respect to a speed of zero and the maximum speed, such asentered at value 276. In FIG. 12, this standard, or default, setting isindicated with a zero at value 282. If the user desires a more rapidramp, then values greater than zero may be entered, and if the userdesires a slowed ramp, then values less than zero may be entered. Anysuitable range of possible values may be used, however, a range ofbetween −10 and 10, and even between −5 and 5 should be sufficient toprovide suitable range of profiles.

In FIG. 13, several profiles are depicted as an illustrative example ofpossible profiles. In FIG. 13, the X-axis corresponds to the relativeposition of the trigger between a resting position and its fullyactuated position. The Y-axis corresponds to the speed or torque,between a zero value and the maximum value, which may be eitherpredetermined or user-selected at values 276 and 278. At 284, a linearprofile is shown and corresponds to the zero value shown in FIG. 12.Also shown are a generally exponential curve 285 and a generallyinversely proportional curve 286, which respectively correspond tovalues below and above zero.

Referring back to FIG. 12, it can be seen that trigger screen 264further includes an offset setting 287, with a corresponding value 288.The offset is measured as a percentage of the maximum speed or torquevalue, and corresponds to the immediate step, or jump, to which thespeed or torque is increased upon any displacement of the trigger fromits resting position. For example, in FIG. 12, offset value 288 is 50,which corresponds to fifty-percent of the maximum speed or torque,whichever is selected at setting 270. Therefore, if torque is selected,then the offset value would correspond to 100 in-lbs, and if speed isselected, then the offset value would correspond to 800 rpm.

Returning to FIG. 13, examples of ramp profiles 284-286 adjusted for theinputted offset value 288 are shown and respectively indicated at289-291. It can be seen that regardless of the offset, the curves allstill terminate at the same maximum value. It should be understood thatprofiles 284-286 correspond to an offset value of zero, while an offsetvalue of 100 corresponds to profile 292, which means that the tool willoperate at a constant speed or apply a constant torque anytime thetrigger is not in its resting position. This constant value correspondsto the inputted or predetermined maximum value.

By selecting a particular ramp profile, the user now can select the rateat which the rotation or applied torque increases or decreases inresponse to the position of trigger 50. Sometimes, however, externalforces will affect the speed of rotation of the work piece or theapplied torque. For example, when a conventional drill is driving ascrew, the bit may be inadvertently withdrawn from the head of thescrew, or the bit may “cam out” of the groove or grooves in the head ofthe screw. When this occurs, the load on the bit is significantlydecreased and the drill will immediately speed up to the maximum speedallowed by the current trigger position. This typically causes the bitto strip the head of the screw, and may also result in damage to thebit. Similarly, when driving a screw or drilling a hole, the bitsometimes binds and is prevented from being rotated further. When thisoccurs, a conventional drill will automatically apply the maximumpossible torque. Because the screw or bit typically remains pinned, theapplied torque instead causes the body and handle of the drill to bequickly rotated with respect to the bit. Unless the user releases thetrigger quickly enough or is strong enough to exert a sufficient countertorque, the user's wrist may become injured by being impelled into anadjacent object or sprained from the sudden, unexpected rotationalmovement. This sudden rotation and impact also may damage the tool.

To prevent, or at least reduce the likelihood of these problems causedby automatic, near instantaneous increases in speed or torque responsiveto external, unintentional forces, the tool includes speed and torquerate delay settings 294 and 296. These settings, with theircorresponding values 298 and 299, shown in FIG. 12, enable a user toselect the rate at which the speed and/or torque adjusts responsive toexternal forces (or the removal thereof). Typically, values 298 and 299are selected from a range of possible values, such as low, medium andhigh values, or a range of numerical values corresponding to a relativerange of delays. For example, values 298 and 299 are respectively shownas zero and ten, which correspond to the end points on a range of zeroto ten. A value of zero corresponds to no delay, and therefore the toolwill operate like the conventional drills discussed above. On the otherhand, a value often corresponds to a relatively large delay, such as aten percent change per second. Other ranges and percentages may be used,and the above are merely presented as illustrative examples.

From default, or home, screen 230, the user may also select distancemode 248. Distance mode 248 makes use of distance sensors 42, each ofwhich is adapted to measure the distance from the sensor to a workpiece. Any suitable distance measuring structure in which a signal isemitted to measure the distance between the emitting unit and an objectmay be used. For example, sensor 42 may emit and detect an infrared orother suitable light signal, an ultrasonic signal, or any other suitableform of distance-measuring signal. In FIG. 1, four sensors are shown(one on the far side of the tool) to measure the distance from above,below, and both sides of chuck 28 to work piece 300. In FIG. 8, threesuch sensors are shown. It should be understood that the number andplacement of the sensors may vary, although typically between one andfour sensors will be sufficient.

Distance mode 248 enables a user to utilize distance sensors 42 toactively or passively control the distance to which a bit or screw isinserted into a surface. When distance mode 248 is selected, the defaultscreen is replaced with a distance screen 302, which is shown in FIG.14. As shown, distance screen 302 includes a setting 304 for selectivelyenabling or disabling the distance mode, as well as a distance setting306 with a corresponding user-selected value 308. After selecting thedistance mode, the user selectively inputs the desired distance at value308. This distance is measured relative to a determined referenceposition on the tool. For example, the distance may be measured from thetip of the chuck, from a portion of the distance sensors, etc. Virtuallyany reference position may be used, so long as the reference position isknown to the user. In FIG. 14, a distance value 308 of 1.3 inches isshown. This distance is also shown on default screen 130 so that theuser can recall the selected distance value without having to return tothe distance screen.

Distance screen 302 includes a reference setting 310, which as shown hasa value 312 of “abs” (or absolute). When the absolute reference value isselected, controller 26 measures the selected distance relative to thedetermined reference on the tool, such as the tip of the chuck. Forinstance, if the distance is 1.3 inches, the controller will considerthe current operation completed when the measured position of theworkpiece is 1.3 inches beyond the tip of the chuck. By way of example,if the user is needs to drive numerous screws with possibly differentlengths flush to the surface of a work piece, the user can select anabsolute distance that is even with the tip of the bit being used todrive the screws. Thus, no matter where the drill starts, it will notconsider the operation completed until the bit, and therefore the screw,is flush with the surface of the workpiece. This features isparticularly useful for installing screws in drywall where it isdesirable to have screws flush with the surface of the workpiece, butvery easy to accidentally over drive the screws.

In a second, relative or “rel” setting, the controller measures thedistance at the when the operation begins, i.e., when the trigger isfirst pulled, and considered the operation completed when the measureddistance is 1.3 inches closer to the workpiece. In this mode, it ispossible to drill a hole of a predetermined depth by placing the drillbit against the workpiece and starting to drill. When the drill is 1.3inches closer to the workpiece, i.e., a 1.3 inch deep holes has beenbored, the controller will consider the operation complete.

As another alternative, the user may record a custom distance, therebyfreeing the user from having to measure the desired distance manually.This option is particularly, useful when the user must repeatedly driveequally sized screws into a work piece. Because the length of the screwsdoes not vary, the user only needs to initially measure the desireddistance and then use this measurement for each subsequent screw.

Upon selection of distance mode 248 and further selection of recordcustom setting 314, controller 26 will prompt the user to place the toolin the desired position, and then to activate one of the user inputbuttons to cause sensors 42 to measure current distance. In absolutemode, this distance is stored in the memory of the controller as thedesired distance. In relative mode, the controller prompts the user toplace the tool in a second position where a second distance is measured.The difference between these positions is then used as the desireddistance.

When the desired distance has been reached, the controller automaticallystops the operation of the tool, or otherwise signals the user, toprevent the desired distance from being exceeded. As an additionaloption, the motor also may be gradually slowed as the desired distanceis approached to reduce the chance of overshooting. This may beaccomplished by any suitable method, such as by shutting off power tothe motor, or by electronically braking the work element, or by applyinga reverse torque to stop the motor more quickly. This feedback mechanismis referred to in FIG. 14 as speed feedback mechanism 324 and includes acorresponding on/off value 326. As an additional option, the motor alsomay be gradually slowed as the desired distance is approached to reducethe chance of overshooting. Other forms of feedback mechanisms to theuser may be used, either alone or in conjunction with each other and/orspeed mechanism 324. For example, sound and visual feedback mechanisms328 and 330, with respective on/off values 329 and 331, are also shownin FIG. 14 and discussed in more detail below. Automatically stoppingthe rotation of the work element may be preferred to many users becauseit prevents the desired distance from inadvertently being exceeded, suchas if a user does not react to the feedback mechanism fast enough, or ifthe user does not detect the feedback mechanism.

Preferably, there are sufficient sensors oriented around the workelement to enable the controller to not only measure the distance towork piece 300, but also to determine the relative angular orientationof the tool with respect to the work piece. In fact, sighting mode 250makes use of such a feedback mechanism. Having multiple distance sensorsoriented in known relative distances to work element 22 and to eachother, the controller can calculate the relative angular orientation ofthe tool with respect to the work piece. For example, in FIG. 4, longaxis 116 of the body of the tool extends at a pitch angle to a normalaxis of work piece 300. In such a configuration, the sensors on thesides of the body will measure the same distance to the work piece,thereby indicating no yaw, however, the upper sensor will measure agreater distance than the lower sensor, indicating a pitch inclination.

Using the relative spacing and orientation of the sensors with respectto each other, the controller can calculate, responsive to feedback fromthe sensors, that tool 10 is inclined at a pitch of, for example, 30°and a yaw of 0° relative to the plane of work piece 300. This feature isuseful when a user wants to drill a hole or drive a screw at aparticular angle into the work piece. The angular orientation describedabove is shown in FIG. 4, in which the above-described pitch angle isgenerally indicated at 332. However, virtually any desired angle may beselected, including both pitch and yaw inclines.

Another useful angle is shown in FIG. 1, in which the drill is orientedcompletely normal to the work piece. This normal orientation wouldtypically be most often used with the sighting mode because it enablesthe user to drill holes or drive screws at right angles to the workpiece. With prior art drivers, screws are often driven in at asubstantial angle off normal. In this event, the user must either leavea portion of the head of the screw exposed and extending at an angle orcountersink the screw into the work piece a sufficient distance that noportion of the head of the screw extends beyond the plane of the workpiece. Unfortunately, with some work pieces, such as drywall, neitheroption is acceptable, with the first leaving an uneven surface, and thesecond resulting in the outer surface of the work piece being punctured,thereby reducing the retaining force of the screw.

Because sensors 42 and controller 26 determine the relative position ofthe tool with respect to the work piece, this determination is madeindependent of the relative orientation of the work piece to the groundor any other surface. Therefore, this feature may be effectively usedeven when the tool and/or work piece extend at an angle to the surfaceupon which the user is standing or to a true horizontal and verticalposition.

When sighting mode 250 is selected, default screen 230 is replaced withsighting screen 334, which is shown in FIG. 15. As shown, sightingscreen 334 includes an on/off setting 336, as well as pitch and yawangle settings 338 and 339. Angle settings 338 and 339 enable the userto input the desired pitch and yaw values 340 and 341. For example, thismay be accomplished by scrolling through a sequence of displayed values,preferably utilizing the chuck for ease of input, or by inputting thedesired value, relative to a reference setting 342 determined byreference frame value 344. Reference setting 342 determines the relativeposition (pitch and yaw) from which angle value 340 is measured. Twoillustrative reference values are “work piece” and “absolute.” When thereference value is “work piece” (abbreviated “WP” in FIG. 15), the pitchand yaw of the long axis of the tool are measured relative to a normalaxis of the workpiece. This configuration is useful when the user wishesto use a selected orientation relative to the plane of the work piece,regardless of the particular angular orientation of the work piecerelative to the ground, true vertical and horizontal positions, etc.

When the reference value is “absolute” (abs), the pitch of the axis ofthe work piece is measured relative to a true horizontal, while the yawis still measured relative to the work piece. The absolute pitch isdetermined by reference to a digital level, such as is well known in theart, incorporated as one of the sensors used by the controller. As aside benefit of providing a digital level sensor, it is possible toutilize the drill as a level. The current pitch inclination angle can bereported on the sighting mode screen or the default screen. By settingany surface of the drill that is parallel to the long axis of the drill,such as the bottom of the battery or the top of the drill, on a workpiece, the angle of the work piece will be reported.

Besides inputting the user's desired angle values and referenceposition, sighting screen 334 enables the user to also select the typeor types of feedback mechanism 346 to be used. Feedback mechanisms 346indicate to the user when the tool is at the selected angle value, andmay also provide signals to the user to properly orient the tool when itis not oriented at the selected angle value. Three illustrative feedbackmechanisms 346 are shown in FIG. 15, and it should be understood thatone or more may be used together, and that there may be other suitablemechanisms as well. As shown, these mechanisms include speed 348, sound349 and visual 350, each with a corresponding on/offsetting 351, 352 and353.

Speed feedback mechanism 348 can take two forms, as with the abovedescribed distance mode. First it can prevent the tool from operatinguntil the tool is oriented in the desired angular position. Once thisorientation is achieved, the controller, responsive to signals from thedistance sensors, enables operation of the tool. Alternatively, thespeed feedback mechanism may slow the drill proportionally to how faroff of the desired angle the drill is oriented. Sound feedback mechanism349 presents an audible signal to the user when the tool is in theselected angular orientation. In a variation of this mechanism, thesound feedback mechanism may emit via microphone/speaker 229 a series ofbeeps or other noises to the user that guide the user in the positioningof the tool. For example, the beeps may become louder, more frequent,and/or change in pitch the closer the tool is to the desired angularorientation, similar to the speed change described. Visual feedbackmechanism 350 presents a visual signal on display 220. For example, inFIG. 11 feedback region 236 is shown. This signal may be as simple as alight or other symbol being displayed on the display when the tool is inthe desired angular orientation. In a variation of the visual feedbackmechanism, arrows or other visual direction-guiding signals arepresented to guide the user to the desired angular orientation of thetool. The feedback region 236 may vary in its size, and it may bedisplayed on a screen other than default screen 230.

Because it is not always be necessary to maintain the exact angularvalue desired, sighting screen 334 also includes a tolerance setting 354with a corresponding tolerance value 355. Using the tolerance, the usercan select the degree of tolerance, or range of error, within which thedesired angular value may be achieved. For example, as shown in FIG. 15,a tolerance value of 5 degrees is shown. Preferably, the feedbackmechanisms (speed, sight and sound) continue to operate within the rangeof acceptable tolerance so that the user receives continuing feedbackwhile the tool is being operated. In addition, the gain of the falloffof speed or other feedback as the angular error increases can be madeproportional to the currently selected tolerance.

Also shown in sighting screen 15 is a constant setting 356 with itscorresponding on/off value 358. The constant setting, when actuated,causes the measured pitch and yaw values to be continuously displayed,such as shown at 360 and 362. These continuous displays alternatively,or additionally, may be displayed elsewhere, such as in feedback region236. By continuously displaying the relative position of the tool withrespect to a work piece, use of the tool as a level is facilitated.

Another mode of operation that the user may selectively utilize is whatis referred to herein as step mode 252. Step mode 252 enables the userto selectively cause the work element to rotate up to a desired numberof revolutions responsive to actuation of either trigger 50 or button38. This includes not only a defined number of complete revolutions, butalso fractions of a single revolution. For example, a defined number ofcomplete revolutions may be useful when the user needs to drive a largenumber of identical screws. On the other hand, a limited number ofrevolutions, or portions thereof, may be desirable when a user hasdriven a screw most, but not all, of the desired distance into a worksurface.

When step mode 252 is selected, step screen 364 is displayed in place ofdefault screen 230. From the step screen, shown in FIG. 16, the user mayselectively enable or disable the step feature with on/off setting 366.Step screen 364 also includes a revolutions (or revs) setting 368. Revssetting 368 enables the user to input at values 370 and 372 the maximumnumber of revolutions which work element 22 will be turned responsive toeach actuation of either button 38 or trigger 50. For example, as shownin FIG. 16, every time trigger 50 is urged from its resting position,work element 22 will complete up to twelve revolutions. Upon return toits resting, unactuated position, trigger 50 may be reactivated to causeup to another twelve revolutions of the work element. Similarly, everyactuation of button 38 will cause one fourth of a revolution of the workelement.

Because trigger 50 is slidable between a range of positions, therebycontrolling the speed of rotation of the work element or the torqueapplied by the work element, the above revs value for the trigger is amaximum number of revolutions. For example, if the user only slightlyactuates the trigger in the speed mode, the work element will slowlystart to rotate. With value 370 being twelve revolutions, work element22 will continue to rotate at a speed indicated by the trigger untiltwelve revolutions are completed. At that time, the selected feedbackmechanism(s) will automatically stop the rotation of the work elementand/or indicate to the user that the desired number of revolutions havebeen completed. If the user returns the trigger to its resting positionbefore the desired number of revolutions are completed, then the counteris reset. Unlike trigger 50, button 38 does not have such an easilycontrolled range of positions. Instead of causing up to a selectednumber of revolutions, actuating button 38 automatically causes theselected number of rotations every time the button is pressed.

Step screen 364 further includes settings entitled staged 372 and echo374, each of which includes a corresponding on/off value 376 and 378.Staged setting 372 corresponds to the revolutions value 372, if any,inputted for trigger 50. Instead of completing up to the inputted numberof revolutions upon actuation of the trigger, and then automaticallystopping or otherwise indicating this fact to the user, staged setting372 calibrates the number of revolutions inputted at revolutions value372 along the range of positions of the trigger. As the trigger isactuated along this range of positions, a proportional number ofrevolutions will be completed, with no further revolutions (or portionsthereof) being completed until the trigger is further urged along itspath. This enables the user to control within a defined range(corresponding to value 372) the number of revolutions of work element22 when the trigger is pulled, for example, to its half-way position.

As an illustration, with the twelve revolutions shown at value 372,pulling trigger 50 one third of its complete range of motion will causework element 22 to complete four revolutions, and then stop. Furtherurging trigger 50 to its half-way position will cause work element 22 tocomplete two additional revolutions, and then stop again. When, and if,trigger 50 is urged to its fully actuated position, then a total oftwelve revolutions will be completed. On the other hand, if the triggeris returned toward its resting (unactuated) position, no furtherrevolutions will be caused. Returning the trigger to its restingposition resets this range of traveled positions, and the user can againcause up to the number of revolutions inputted at value 372.

The staged function of the step mode can also be implemented so thatadditional revolutions can be obtained without completely releasing thetrigger. In such an embodiment, if the trigger is pulled halfway and sixrevolutions are completed, the user may partially release the trigger toallow additional revolutions to be selected. Thus, with the triggerpulled halfway, if the user relaxes the trigger to a one-quarter pulledstate, no additional revolutions will be completed, however, if the userthen pulls the trigger back to the halfway state, three more revolutionswill be provided. Similarly, this function can be implemented so that ifthe user relaxes the trigger prior to completion of the maximum selectednumber of revolutions, the chuck will stop when the trigger positionreaches the position corresponding to the number of revolutions thencompleted.

Echo setting 374 causes work element 22 to repeatedly complete anincremental number of partial or complete revolutions as long as thetrigger is held at its fully actuated position. Unlike the revolutionsduring conventional operation of a hand tool, the incrementalrevolutions (complete or partial) in the echo setting are spaced-apartby time delays. The delay does not need to be long, but should be ofsufficient duration for the user to determine if further rotation isnecessary. For example, a duration of anywhere in the range ofapproximately one-tenth of a second to five seconds are preferred, witha duration of less than approximately one second being most preferred.

As shown in FIG. 16, echo setting 374 includes an on/off value 378. Inthe on position, echo setting 374 causes a predetermined default amountof rotation for every time increment that the trigger is held in itsfully actuated position after the selected number of revolutionsdetermined by value 372 have been completed. This predetermined echo ofrotation may be within the range of approximately one-thirty-second of arevolution to approximately two revolutions, with values of one eighth,quarter and half, a revolution being preferred. Alternatively, insteadof a predetermined amount of rotation, the user may input a revs valuewhich determines the amount of rotation per time increment that thetrigger is held in its fully actuated position after the completion ofthe selected number of revolutions. This alternative setting 380 andcorresponding value 382 are also shown in FIG. 16 for purposes ofillustration. When step screen 364 includes a revs value 382 input, theon/off value 378 may be omitted, with the same result being accomplishedwith a revs value 382 of zero or non-zero. In addition, the timeincrement before and between echo revolutions could be selected by theuser in place or in addition to the revs setting. In that case, thebutton step revolution value may also be used for the echo revolutionvalue.

Sometimes a user does not know the desired number of rotations, but theuser knows that he or she will need to drive a large number of identicalscrews. In such a situation, the user may determine the desired triggerrevolutions value 372, such as through trial and error, or the user mayutilize record custom setting 384. Record custom setting 384 measuresthe number of rotations of work element 22 during the recording period.When selected, the number of revolutions, as measured by internalfeedback sensors and stored by controller 26, is determined by thecomplete operation (start through stop) of the tool. Controller 26 mayalso cause directions to be displayed on display 220 or played throughspeaker/microphone 229 to tell the user, for example, to position thetool and actuate the trigger to begin recording, with the recordingstopped when the trigger is returned to its resting position. Uponcompletion, the user may be prompted to accept the recorded measurement,or to rerecord the measurement. It should be noted that the recordcustom operation may selectively also record the speed profile of thechuck as the revolutions are completed. Thus, in addition to thecompleting the same number of revolutions, the controller would causethe chuck to maintain the same speed profile as recorded in the samplerun. For instance, it may be desirable to use a slow speed at thebeginning and end of the revolutions, with a higher speed in between.

When the user records a custom number of rotations, the user alsoselects via “use custom” setting 385 and toggle value 386 whether thisrecorded number of revolutions is used for the trigger value or thebutton value. If used for the trigger value, then up to this recordednumber of revolutions, at a speed selected by the trigger, are causedresponsive to the trigger position. If used for the button value, thenthe measured number of revolutions and recorded speed profile areautomatically caused when the button is depressed.

Also shown in FIG. 16 are ramp up 387 and ramp down 388 settings. Thesesettings enable the user to selectively define the profile through whichthe speed of rotation or applied torque is added at the initial portionof the defined number of rotations (ramp up) or reduced at the latterportion of the defined number of rotations (ramp down). The values 390and 392 of these profiles may be established profiles, such as high, lowand medium values, or they may correspond to a relative range ofprofiles, such as those shown in FIG. 13.

In the embodiment described above, the rotational position of the workelement in step mode 252 is positively controlled. Therefore, power willbe supplied to the motor, up to any established maximum speed and torquesettings, until the work element, such as chuck 28, completes theselected amount of rotation. This is in contrast to U.S. Pat. No.5,754,019 (the disclosure of which is hereby incorporated by reference),which discloses applying a series of torque pulses after a predeterminedthreshold torque is reached. In such a system, the degree of rotation,if any, of the work element may vary, depending on such factors aswhether the applied torque exceeds the required torque to rotate thework element, the amount of resistance encountered at each pulse, etc.Therefore, power will be applied to the motor in spaced-apart pulses,and it is the magnitude and timing of these pulses that is controlled,not the actual rotation of the chuck. The disadvantage of such a systemis that no actual movement of the work element will occur when theapplied torque is less than the load.

Although the various step modes described above are preferablyimplemented with positive rotation control, it should be understood thatthe various step modes of the present invention could also beimplemented with incrementally applied torque. One of the benefits of aposition sensor to detect rotation is facilitating positive revolutioncontrol, such as for the step mode, or for more direct control of speedin other modes.

Another mode of operation that the user may selectively actuate fromdefault screen 230 is tap mode 254. Tap mode 254 is used when the userneeds to tap threads in a work piece. When tapping a hole, dislodgedpieces of the work piece tend to bind the tap unless these pieces arebroken loose periodically by reversing the tap. Conventionally, the usermanually operates a drill until the tool binds, or until the userdecides the tool is likely to bind. At this point, the user stops thedrill, reverses the direction of rotation of the tap, and operates thedrill in this reverse direction while partially or completelywithdrawing the bit from the hole to remove these unwanted pieces.

Tap mode 254 automates this process through the selection of the maximumnumber amount of applied torque and maximum number of rotations in theforward direction before automatically reversing the direction ofrotation for a determined number of revolutions. Upon selection of tapmode 254, default screen 230 is replaced by tap screen 394, which isshown in FIG. 17. Tap screen 394 includes an on/off setting 396 throughwhich this mode of operation is selectively enabled and disabled. Whenenabled, the user may input values 398 and 400 for torque 402 andrevolutions (revs) 404 settings to establish the values at which thetool reverses the direction of operation. The number of revolutions inthis reverse direction may be selectively controlled by the user, suchas with reverse setting 406 and user-inputted value 408 on screen 394.Alternatively, these values may be predefined. Between approximatelyone-quarter and approximately five revolutions will generally besufficient for both the forward and reverse directions. Of course, it iswithin the scope of the invention that values outside of these exemplaryranges may be used, depending on the particular conditions encounteredand a user's particular preferences.

Another mode of operation is security mode 256. Security mode 256enables the user to selectively lock, or prevent operation, of the tooluntil a passcode is supplied by the user. The likelihood of theft oftools including this feature will be substantially reduced relative toexisting designs because the tool is useless without the requiredpasscode. Upon selection of security mode 256, default screen 230 isreplaced with security screen 410, which is shown in FIG. 18.Preferably, the controller 26 will not to deliver power to the motorunless the correct pass code is entered. Because bypassing thecontroller is difficult or impossible, there is little likelihood that athief will be able to make use of a stolen tool.

Similar to many of the previously described screens, security screen 410includes an on/off setting 412 through which this mode of operation isselectively activated or deactivated. In addition, security screen 410also includes a code setting 414, with a corresponding value or values416, which correspond to the user's passcode or combination. Thispasscode may include a sequence of indicia, such as letters, numbers orother symbols, which are inputted by the user. In addition to scrollingthrough a series of possible indicia via arrow buttons 224 and 226, thevalues may be scrolled through responsive to the rotation of the chuck.Because the chuck may be rotated in both clockwise and counterclockwisedirections, it provides a mechanism much like the dial on a combinationlock, through which the user may selectively input indicia forming theuser's passcode.

In fact, the tool preferably includes markings on its body adjacent thechuck corresponding to the indicia input as values 416. As an example,in FIG. 19, a portion of body 12 and chuck 28 is shown. In FIG. 19, aplurality of indicia, in this case numbers 418, are shown adjacent chuck28, and chuck 28 includes a pointer 420 which indicates the selectedvalue. In FIG. 19, numerals 0-9 are shown, however, it should beunderstood that typically numerals or other indicia will extend at leastsubstantially around the chuck, and that other ranges of values may beused. Because the tool includes internal feedback sensors thatcommunicate the rotational position of the chuck to the controller, thecontroller can monitor the currently selected indicia, such as thenumeral five shown in FIG. 19, or the relative rotation as describedbelow. Similarly, upon either actuation of a button or the trigger, orupon rotation of the chuck in the opposite direction, the controller canaccept the current value and begin scrolling through the range ofindicia to be inputted next.

The locked configuration of the security mode may be selected in anactive fashion, by pushing a corresponding button or activating thefeature directly. Alternatively, the tool can have an inactivitytime-out period after which the security mode is activated to lock thetool. For instance, if the tool is not operated for a period of time,such an hour, several hours, eight hours, etc., the security mode may beactuated. This time period may be predetermined, or selected by the uservia a suitable user input. In addition, the security mode may beactuated any time the battery is removed and replaced, either with thesame battery or a different battery. By selection of the appropriatetriggering event, the theft deterrent effect can be achieved withminimal impact on the authorized user.

It should be noted that some variable speed tools are provided with amechanical high-speed bypass of the electronic speed control for fullspeed operation. It may be preferable to eliminate this feature whenimplementing a security mode. However, it is also possible to allow thehigh-speed bypass to remain, while the controller simply disablesvariable speed operation. The significant loss of utility created bylack of variable speed operation should provide discouragement to mostpotential thieves.

In the embodiments of security mode 256 described above, the tool isrendered inoperable after a either period of nonuse, removal of powersource 24, or manual actuation of the security mode by the user. To makethe tool usable again, the user has to enter a passcode, which enablesthe tool to operate until another one of these triggering events occurs.

It is also within the scope of the present invention that security mode256 may define a period of operability, instead of, or in addition to,the period of inactivity described above. By this it is meant that uponactuation of the security mode, such as by entry of the user's passcode,the tool will be usable for a determined maximum interval. This intervalmay be in units of any selected value that may be monitored by a counterto determine whether a defined maximum value has been exceeded. Examplesof suitable intervals include, but are not limited to, time periods,such as days, hours or minutes, revolutions of work element 22, batterycycles, and actuations of trigger 50. For purposes of discussion, theinterval will be discussed as units of time, and more particularly ashours measured from when the user's passcode is entered.

By referring back to FIG. 18, security screen 410 can be seen to includeseveral settings and values specific to this embodiment security mode.As shown, these settings include a units setting 530, a maximum valuesetting 532, and power and idle disconnect settings 534 and 536. Alsoshown in FIG. 18 is an elapsed units indicator 538. Units setting 530enables a user to select at value 540 the particular units to bemonitored by the counter. As discussed above, examples of suitable unitsare hours, days, revolutions, battery cycles and actuations of thetrigger. Once the user has selected the units to be used by the counter,a maximum value 542 is entered to define the maximum number of theselected units that may be counted before the controller disables theoperation of the tool.

From screen 410, the user also may select, via power disconnect setting534 and its corresponding on/off value 544, whether the controller willcause the tool to be disabled every time the tool's power source, suchas battery 54, is disconnected. For example, the user may prefer to beable to remove and replace battery 54 without having to reenter theuser's passcode, which will also reset the counter. Idle disconnectsetting 534 may be used in a similar manner to cause the controller todisable the operation of the tool if the tool has been idle for adefined time period, which is entered at value 546. It should beunderstood that a value of zero at 546 would indicate that the idledisconnect is not being utilized. When the power and idle disconnectsare not selected, then the tool will remain operational until themaximum value is reached. When either of these disconnects is selected,then the tool will remain operational until either maximum value 542 isreached, or until either disconnect is triggered.

Elapsed units indicator 538 displays at 548 the number of the selectedunits which have occurred, or elapsed, since the user's passcode wasentered. It should be understood that value 548 is displayed in the sameunits selected with units setting 530. As configured in FIG. 18, thecounter measures the hours that have passed since the user's passcodewas entered, and the tool will be rendered inoperable by the controllereither when twenty-four hours have elapsed or when the tool has beenidle for two consecutive hours. As shown, six and one-half hours haveelapsed since the user's passcode was entered, and the tool has beenidle for two consecutive hours.

When a tool includes security screen 410 with the settings discussedabove, entry of the user's passcode should be required before allowingsettings 530-536 to be adjusted. For example, upon toggling to thesecurity screen, the user would enter passcode 416 and then selectivelyadjust the values 540-546 corresponding to settings 530-536. It shouldbe understood that any of these settings, values and indicators may bepreprogrammed into controller 26, and therefore not selectivelyconfigurable by the user. Similarly, any of these values may be inputtedvia interfaces or inputs other than the security screen shown in FIG.18. Also, not all of these settings and indicators are required toimplement this embodiment of security mode.

A schematic diagram for this embodiment of security mode 256 is shown inFIG. 26 and generally indicated at 550. As shown, the previouslydescribed controller 26 and motor 20 from FIG. 7 are shown. For purposesof illustration, the other elements of FIG. 7 have not been reproducedin FIG. 26. It should be understood, however, that the security mode maybe implemented without requiring all of the elements shown in FIG. 7. InFIG. 26, the controller is shown including a counter 552 that is startedwhen the user's passcode is inputted via any of the user inputsdescribed herein, which are generally indicated at 554. Any of the othervalues described above may also be entered through a suitable userinterface, such as security screen 410, to the controller's processor556. The selected or preprogrammed maximum value is stored in thecontroller's memory 558, which preferably includes a non-volatileportion so that the maximum value is not lost from memory when the toolis disconnected from power source 24.

As shown, the controller includes a power source 560 that is separatefrom the primary power source 24 of the tool, and which may be used toprovide power to any or all of counter 552, processor 556 and memory558. Power source 560 will typically be a battery, such as used withwatches, cameras or the like. Power source 560 may also include acapacitor charged by power source 24. At a minimum, power source 560should provide power to counter 552 so that the counter continues tooperate even if the rest of the tool is disconnected from primary powersource 24. Even if no other portion of the controller is powered bypower source 560, the security mode will continue to operate. Uponreconnection of the tool with power source 24, the controller, namelyprocessor 556, will determine if the counter has exceeded the storedmaximum value. If so, the tool will be disabled until the user'spasscode is entered. When memory 558 does not include a non-volatileportion in which maximum value 542 is stored, then power source 560should also provide power to memory 558.

Once the user's passcode is entered, counter 552 begins monitoring thenumber of the selected units that have occurred, or elapsed, since thepasscode was entered. Processor 556 compares the measured units to themaximum value stored in memory 558 to determine if this maximum valuehas been exceeded. When this occurs, the controller disables theoperation of the tool, such as by controlling its electronic speedcontrol to prevent the delivery of power to the motor. Counter 552 orprocessor 556 may also monitor the time during which the tool is idleand compare this measured idle time to a selected maximum idle timestored in memory 556. Every time the trigger is actuated or the tool isotherwise used, the idle time resets to zero. Similarly, if the user'spasscode is reentered once the counter is started, then the counter isreset. If battery 54 is disconnected from the tool or if the batteryexhausts its charge, a signal is sent to processor 556. If powerdisconnect 534 is in its on mode, then the processor disables the tooluntil the user's passcode is reentered.

An example of a situation where this embodiment of security mode 256 maybe desirable is when tools must be checked out from a tool crib, orother central depository. In such a situation, the person checking thetools out to others can actuate the security feature to start thecounter, and thereby define the maximum operable time period for thetool, without having to give a passcode to the user. Therefore, if theuser keeps the tool, rather than returning it to the crib, the toolbecomes inoperable after expiration of the maximum operable interval andthe user lacks the passcode required to render the tool operable again.Therefore, theft by employees, subcontractors and temporary employees isdeterred, in addition to theft from others.

Both embodiments of security mode may be implemented concurrently. Whenthis occurs, entry of the user's passcode will define the start of amaximum operable interval during which the tool may be used withoutrequiring reentry of the user's passcode. However, if a defined periodof nonuse elapses or if the tool's power supply is removed or exhausted,then the passcode would have to be reentered even though the maximumoperable interval has not expired.

When any embodiment of security mode 256 is used, the tool preferablyincludes prominent security indicia on its housing to signal topotential thieves that the tool includes a security feature that willrender the tool inoperable unless the required passcode is known. Anexample of such an indicia is shown in FIG. 27 and generally indicatedat 562. It should be understood that the size, placement and shape ofindicia 562 may vary, however, it should be or suitable size andposition that would be thieves will notice the indicia and thereby bedeterred from stealing the tool.

Counter 552 may also measure one or more cumulative operational valuesfor the tool and store these values in a non-volatile component ofmemory 558. For example, the counter may measure such values as thetotal number of revolutions of the work element, the total hours (orother time unit) of operation, the total number of times the trigger isactuated, the total number of amp-hours used, and the total batterycycles. Any of these values may be used for warranty purposes by themanufacturer of the tool. Because some users rarely use their tools,while others use their tools for dozens of hours each week, it iscurrently difficult for manufacturers to have a warranty fair to allusers. Furthermore, a timer that starts running upon first operation ofthe tool by a use can provide verification of the age of a tool fordetermining warranty coverage.

Typically only the date a particular tool is manufactured is known.Sometimes the purchase date may also be known. Regardless, trying towarranty the performance of the tool for a defined time period from thepurchase or manufacturing date may be unfair to users that onlyoccasionally use their tool, or only use it for light duties, becausethe warranty period will be typically be determined as an average valuebased on the theoretical average user. Therefore, too long of periodwill be given for some more-frequent, heavier-duty users, while tooshort of period will be given for less-frequent, lighter-duty users. Bymeasuring and storing a cumulative operational value of the tool, it isnow possible to issue a warranty that is fair to all users, regardlessof the time period needed for the user to reach the warrantied value.For example, the performance of the tool may be guaranteed for suchvalues as one million revolutions of the work element, or 1000 hours ofuse, or 5,000 amp-hours.

Another selective mode of operation shown in FIG. 11 is chuck hold mode258. Chuck hold mode 258, with its corresponding on/off setting 422,enables the user to selectively determine whether chuck 28 is heldstationary or freely rotatable when the drill is not operating. Withchuck hold mode 258 deactivated, the chuck may be rotated manually bythe user in either the clockwise or counterclockwise direction when thechuck is not being electronically driven as in conventional drills.

However, sometimes it is desirable to be able to use the tool in amanner similar to a non-powered tool. When chuck hold mode 258 isactuated, the controller, by virtue of an electronic chuck control,actively holds the chuck in place when the trigger is not actuated. Thecontroller locks or holds the chuck in place by applying a torque to thechuck to counteract whatever initial rotation is sensed when the triggeris not actuated. As previously described, the controller typicallymonitors rotation of the chuck by tracking rotation of the motor, thechuck or some component in the drive train. Thus, if the controllerdetects a spontaneous rotation, it can counteract the rotation byengaging the motor up to the level of the maximum available torque.

By way of example, the chuck lock mode allows a user to manually adjustthe final depth of installation of a screw after the trigger is releasedby rotating the body of the drill. With the chuck locked, the drillessentially becomes a manual screwdriver allowing the user to impart anadditional fraction of a revolution with much finer control than couldbe accomplished by activating the motor using the trigger with existingdrills. Of course, the above described step mode offers similarfunctional benefits. The chuck lock mode also simplifies installationand removal of bits from the chuck because the user can simply turn theshell of the chuck by hand to tighten or loosen the jaws of the chuck.Without the chuck hold, the user would have to grip the base of thechuck with one hand while rotating the shell with the other, which canbe awkward for the user.

Also shown in FIG. 11 is voice recognition mode 260 with itscorresponding on/off setting 424. When a tool includes this mode ofoperation, controller 26 includes a voice recognition processor thatenables the user to select any of the above modes of operation and inputany of the above user inputs via speaker/microphone 229. Controller 26receives these voice commands and converts the audio signals intoelectronic commands, similar to those received via actuator 50, button38 or any of the other user-input buttons described herein. Thedisclosures of the following U.S. patents are hereby incorporated byreference to provide examples of suitable mechanisms and systems forvoice-recognition interfaces for electronic devices: U.S. Pat. Nos.5,247,580, 5,255,326, 5,267,323, 5,749,072, 5,774,859, 5,809,471. Onebenefit of the voice recognition feature is that can enable many of thefeatures described herein to be implemented without a user interfacedisplay, thereby potentially eliminating the associated cost.

Yet another mode of operation which may be selected from default screen230 is pressure-activated torque mode 262, with its corresponding on/offsetting 426. This mode may also be referred to as push mode. This modeof operation enables the torque applied by work element 22 to beselectively controlled by the pressure the user exerts on tool 10.Therefore, as the user exerts greater force upon the tool, the appliedtorque is commensurately increased up to a determined maximum value,such as may be established from trigger mode 246 or by manual torquecontrol 30. The user-applied force may be measured by the force exertedupon work element 22, as sensed by transducer 219. Alternatively, thetool may include a force-sensing region, such as the pad shown at 221 inFIG. 9 on the rear surface 136 of the housing. Such a pad may also belocated on body 12, handle 16, or in any other suitable location on atool.

The user-applied force may be measured by the force exerted upon workelement 22 as sensed by a transducer, such as transducer 219 in FIGS. 9and 10. For a drill like the one shown in FIG. 1, a transducer 219 maybe positioned between a motor 20 and a gear box 620, as shown in FIG.27. Alternatively, the tool may include a force-sensing region, such asthe pad shown at 221 in FIG. 9 on the rear surface 136 of the housing.Such a pad may also be located on body 12, handle 16, or in any othersuitable location on a tool. The measured value of the user-appliedforce may then be used to control the torque applied by work element 22,such as by regulating the supply of power to motor 20, as explainedabove.

A mechanical arrangement also may be used to control the torqueaccording to a user-applied force. A simple illustration of this isshown in FIG. 28. A motor 20 is shown driving a shaft 650. A disc 652 isfixed to the end of shaft 650. A second disc 654 is attached to a shaft656 that turns a chuck 28. Pushing disc 652 in the direction of arrow658 causes the disc to contact disc 654. Friction between the discs thencauses disc 654, shaft 656 and chuck 28 to rotate. The friction betweenthe discs is proportional to the force with which disc 652 contacts disc654, so the harder a user pushes, the greater the torque applied to thechuck. In this embodiment, the discs are made from any suitablematerial, such as a hard plastic. Preferred materials have a dynamicsliding frictional coefficient that is similar to the static coefficientto avoid abrupt transitions in torque.

Another embodiment is shown in FIG. 29. Again, a motor 20 drives a shaft650, and a disc 660 is fixed to the end of the shaft. Disc 660, however,includes a stepped surface 662 instead of a flat surface. A disc 664 isattached to shaft 656 and chuck 28. Disc 664 includes a surface 666 withrecesses configured to mesh with the steps on surface 662 of disc 660,and deformable material 668 is positioned within the recesses. Pushingdisc 660 toward disc 664, in the direction of arrow 670, causes thesteps to contact the deformable material in the recesses. That contactcreates friction, which, in turn causes disc 664, shaft 656 and chuck 28to rotate.

The steps on disc 660, the recesses in disc 664, and the thickness ofthe deformable material are sized so that the contact between the discsincreases as more force is applied. For example, disc 664 includes acenter recess 672 filled with deformable, elastomeric material, and disc660 includes a center step 674. When disc 660 is pushed toward disc 664,center step 674 contacts the deformable material in center recess 672,creating friction and torque. However, the other steps and recesses areconfigured so that they do not yet contact each other. As a user pushesdisc 660 further, step 674 deforms or compresses the material in recess672, and disc 660 moves closer to disc 664 until another step contactsthe deformable material in a corresponding recess, creating additionalfriction and torque. Pushing disc 660 still further toward disc 664compresses the deformable material further, and another step contactsdisc 664 creating still more friction. Of course, different numbers ofsteps and recesses may be used. The torque applied to shaft 656increases as steps that are radially further away from shaft 656 contactdisc 664 because the torque is the product of the force and the distancebetween the line of action of the force and the axis of rotation. Thisarrangement provides a progressive or exponential increase in torquewith pressure rather than a linear increase as occurs in the firstdescribed embodiment.

Another mechanical embodiment of a system to provide torquecorresponding to the force applied by a user is shown in FIGS. 30 and31. A motor 20 rotates a shaft 650, which in turn rotates a somewhatflexible disc 680. Disc 680 contacts a disc 682 mounted on shaft 656 tochuck 28. As shaft 650 turns, friction between discs 680 and 682 causesshaft 656 and chuck 28 to rotate. In this embodiment, the periphery ofdisc 680 curves away from disc 682, as shown. The periphery of disc 680curves away from disc 682 so that the periphery may be selectivelybrought into contact with disc 682 to increase the proportionalityconstant between the pressure applied and torque transferred to thedisc. The proportionality constant changes because, for a given pressureor normal force, the torque transferred will be proportional to theradial distance from the axis where the force is transferred.

The embodiment shown in FIG. 30 includes discs 684 and 686 mounted onshaft 650. Shaft 650 passes through discs 684 and 686 in such a way thatthe shaft may turn without rotating discs 684 and 686. However, discs684 and 686 are mounted on shaft 650 so that they are held at a fixedposition along the shaft; the discs may not move along the length of theshaft. Additionally, discs 684 and 686 are mounted on shaft 650 so thatthe discs may rotate relative to each other. Discs 684 and 686 hold aplurality of bearings 688 against disc 680. In FIGS. 30 and 31, bearings688 are shown as ball bearings, but any other suitable bearing may beused. The bearings push against disc 680, but allow disc 680 to rotaterelative to discs 686 and 684. The bearings are mounted in slots 690 and692 in discs 684 and 686, respectively. The slots are shown in FIG. 31.Slots 690 extend radially outwardly in disc 684, while slots 692 curveoutwardly in disc 686, as shown. Slots 690 and 691 are configured sothat the bearings move outwardly or inwardly in the slots when discs 684and 686 rotate relative to each other. For example, as disc 684 in FIG.31 is rotated clockwise relative to disc 682, bearings 688 moveoutwardly in slots 690 and 691. In FIG. 31, the bearings are shownfurther outward from shaft 650 than shown in FIG. 30.

In FIG. 30, disc 686 is held stationary, and disc 684 is rotatedrelative to disc 686 by a gear 690 that meshes with splines or ridges onthe edge of disc 684. Gear 690 is positioned partially outside a toolhousing so that a user may move the gear by gripping and rotating it.Rotating gear 690 causes disc 684 to rotate relative to disc 686,thereby moving bearings 688 inwardly or outwardly. If the ball bearingsare moved outwardly, they push the periphery of disc 680 against disc682, thereby increasing the pressure/torque proportionality constant.

As shown, the peripheries of discs 680 and 682 also include tapered andmeshing annular extensions and recesses, such as extension 692 andrecess 694. When the periphery of disc 680 is pushed against theperiphery of disc 682, the tapered extensions move into the recesses indisc 682. The extensions and tapers should be configured so that theextensions will slide in the recesses without locking in place, but theyshould be configured so that there is friction between the extensionsand recesses. That friction will increase the pressure/torqueproportionality constant more than occurs by virtue of moving thetransfer point further from the axis. Extension 692 may be longer andrecess 694 may be deeper than the next most inward extension and recess.Additionally, the taper of extension 692 and recess 694 may be moresteep than the taper of the next most inward extension and recess. Eachof these details further increases the change in the proportionalityconstant above and beyond the linearly increasing radial contact point.Various numbers of extensions and recesses may be used, including discswith no recesses and/or extensions. Other friction enhancing devices maybe used instead of or in addition to tapered extensions and recesses.For example, the contacting surfaces on the peripheries of discs 680 and682 may be roughened to increase the friction between the discs.

FIGS. 32 and 33 shown another embodiment of a system to provide torquecorresponding to the force applied by a user to a tool. This embodimentis similar to the embodiment shown in FIG. 30, except that thisembodiment uses a series of cams to push the periphery of disc 680against disc 682. Three cams are shown at 700, mounted on a shaft 702.Shaft 702, in turn, is mounted to the housing of the hand tool. Cams 700hold ball bearings 704 against disc 680. The cams may be rotated, asshown in FIG. 33, by turning shaft 702 so that the ball bearings pushdisc 680 against disc 682. Shaft 702 may be rotated by a lever 690 thatextends from the shaft. FIG. 32 shows two sets of cams, but one or moresets may be used. Additionally, the sets may include various numbers ofcams, including more or less than shown in FIGS. 32 and 33.

One benefit of push mode 262 is that it prevents stripping of screwheads where the torque applied exceeds what can be transferred to thescrew without causing the bit “cam out,” where the bit is pushed out ofthe screw head. Once the bit is pushed out of the screw head, the bitusually starts to spin rapidly, thereby quickly auguring out the driverecess in the screw. Although the rate delay at which the speedincreases, as described above, partially addresses this problem bylimiting rapid speed changes, it does not eliminate the problem ofexcess torque relative to the axial force being applied between the bitand the screw head.

Upon selection of push mode 262, default screen 230 is replaced by apush screen 430, depicted in FIG. 20. Push screen 430 allows the user toselect a predefined relationship between the maximum torque that will beapplied to the chuck, as set in the trigger mode, and the axial pressureor force being applied to the screw. The push mode screen is similar tothe trigger mode, except that the torque curve is adjusted as a functionof the applied force rather than as a function of trigger position.Otherwise the available adjustments are the same. In particular, anon/off setting 432 allows the user enable or disable the push feature. Aprofile setting 434 having a user value 436 allows the user to selectthe curve or profile relating the torque output as a function of forceapplied. The curve relating torque to pressure can be changed fromexponential to linear to inversely exponential by selecting a negative,zero or positive value, respectively.

A torque offset setting 438 having a user input value 440 allows theuser to select the initial torque value for threshold applied force.When driving a screw with a drive socket that does not tend to push thebit out of the screw, such as a hex or square drive, it may be desirableto allow some torque to be applied even with no axial force. A max forcesetting 442 having a user selectable value 444 allows the user todetermine the full-scale force required to reach the maximum availabletorque. A force offset setting 446 having a user input value 448 allowsthe user to select a force threshold which prevents any torque frombeing applied until the threshold force has been achieved. In otherwords, if the max force value is forty pounds, and the force offset isten percent, no torque will be applied until the axial force reachesfour pounds. At this point the torque applied will start at a leveldetermined by the torque offset.

FIG. 21 illustrates various types of push profiles available. Theforce/torque curve for zero force and torque offset and linear profileis illustrated at 450. In this case torque is linearly dependant on pushfrom zero to maximum. Curve 452 illustrates the effect of a force offsetwith zero torque offset and an exponential profile. Curve 454illustrates the effect of a torque offset with zero force offset and ainversely exponential profile. Curve 456 illustrates having both torqueand force offsets and an exponential profile. In such a situation, notorque is applied until the threshold force is reached, at which pointthe torque jumps to the offset value.

In push mode, the operator typically places the bit lightly against thescrew and depresses the trigger. Unless there is a torque offset, notorque will be supplied to the chuck and therefore no rotation willoccur until the threshold force is applied. As the user begins to pressagainst the screw, the rotation starts, with the torque being limited toa maximum value determined by the current pressure. By selecting aproper curve and maximum torque, it is possible to partially orcompletely eliminate the problem of the bit being pushed out of thescrew head. By using the push mode, a user can control the driving of ascrew by how hard they push on the drill, effectively “pushing” thescrew into the work piece.

As with the trigger mode, there will be a gradual transition betweenzero speed and the speed set by the trigger which is dependant on howmuch the axial pressure or force exceeds the currently required minimumfor the torque being utilized. The relationship between excessive forceand speed is determined by a gain setting 458 with a setting 460,similar to that described for the trigger mode. The position of thetrigger can be utilized to select a desired maximum speed at any giventime.

It should be understood that the previously described screens, userinput controls and related options have been presented as non-limitingexamples of possible screens, controls and options, each of which may beused with any of the embodiments of the tool (tools 10, 90 and 130)described herein or with other portable power tools. Similarly, eachparticular function may be used alone or with other functions, and theorder, display and grouping of functions and screens may vary withoutdeparting from the scope of the invention. For example, the displayillustrated in the figures is sized to include multiple lines of text,as well as the battery and feedback regions. A smaller display may onlyinclude a single text line, in which the various settings areincrementally displayed.

Additionally, many of the modes of operation and settings discussedherein may be implemented without requiring a user interface with avisual display. As an example, in FIG. 22, a plurality of user-operablecontrols are generally indicated at 460 on the body 462 of a tool. Thistool may be any of the previously described hand tools, such as tools10, 90 and 130, or may be any other type of conventional hand tooldescribed herein in which it is desirable to implement one or more ofthe modes or settings of the present invention. In FIG. 22, threecontrols are shown at 464, 466 and 468 in the form of switches, however,it should be understood that other manually operable controls, such asbuttons, dials, slides, etc. may be used. Also, it should be understoodthat as few as one or two controls may be used, and as many as necessaryto implement and allow the user to select among the desired number offeatures. A DIP switch block 478 is shown with six individual switch480. Use of a DIP-type switch block allows many different options to beselected in a relatively compact space. Individual switches can be usedto turn various features on or off and select between various levels.

As an example, echo setting 374 may be implemented via switch 464. Bytoggling between the on and off values of the switch, the user canselectively enable and disable echo setting 374. In such animplementation, a predefined value, such as one-quarter or one-half of arevolution per second may be used. Alternatively, rotary dial ormulti-position dial or slide may be used to select this value. Anexample of such a dial is also shown in FIG. 21 at 470 and includesindicia 472 surrounding the dial to reflect particular values that maybe selected using the dial. In FIG. 22, indicia 472 are illustrated ashatch marks, however, any suitable symbols, numbers, letters, etc. maybe used.

Another example of a feature, or mode, of the present invention that maybe implemented without requiring a user interface with a visual displayis push mode 262. For example, switch 466 may allow the user toselectively enable push mode 262. As such, toggling the switch betweenon and off settings selectively enables and disables push mode, with apredefined maximum applied torque and ramp profile. Alternatively, oneor more dials, such as dial 482 can be used to set a maximum torque orselect an appropriate profile.

Trigger mode 242 may also be implemented with a single switch, such asswitch 468. In such an implementation, the two positions of the switchenable a user to select between the trigger controlling speed or appliedtorque. Dials or controls can be provided to enable selective control oframp profiles and maximum values. Alternatively, a standard, predefinedramp profile and predefined maximum values can be used. Chuck hold andvoice modes 258 and 260 may also be controlled with on/off switches.

In the case of a drill or driver with a rotary chuck, or other tool witha rotary output, security mode 256 does not necessarily even require aswitch to be implemented. Because rotation of the chuck may be used, asdescribed herein, to selectively input a user's passcode or combination,the user can simply use the chuck to enter this code whenever required.Alternatively, an on/off switch may be used to enable the user toselectively engage the security mode by selecting the on position of theswitch. Of course, in such an implementation, moving the switch to itsoff position will not disengage the security mode. Instead, the user'spasscode must be entered. Also, a light or audio signal may be used toindicate to the user that a passcode must be entered to disengage thesecurity mode. An example of such a light is shown in FIG. 22 at 474. Aspeaker has previously been illustrated at 229, and alternatively abuzzing or other tone may be selectively emitted from internal thetool's housing.

It should be noted that rotation of the chuck may be sensed bymonitoring rotation of the motor. Monitoring rotation of the motorgenerally provides greater accuracy because of the gear reduction thattypically occurs between the motor and the chuck. Thus the motor mayturn ten times for every revolution of the chuck. However, as aconsequence, if the gearing skips or a manual chuck is utilized, theremay be no direct positional correlation between the position of themotor and the position of the chuck. As a result, rotation of a pointeron the chuck to a specific combination number on the housing may not bedirectly detectable. Rather only the subsequent relative rotation of thechuck may be determined. Therefore, the passcode or combination may bedetected by the controller only as a series of relative positions, suchas a rotation of 420 degrees clockwise, followed by a rotation of 90degrees counterclockwise, followed by a rotation of 30 degreesclockwise. When the controller detects this pattern of rotation the toolcan then be unlocked.

In addition, a sensor configured to detect relative movement isgenerally much simpler than one capable of tracking absolute position.For example, one or more magnets attached to a rotating component of thedrive train can be detected by a hall-effect sensor to detect relativemovement. Similarly, relative rotation can be detected providing arotating member with perforations that periodically pass a beam of lightthat can be detected by a photo-diode or phototransistor. For example, aslotted optical switch, such as a Motorola H21A can be positioned in themotor to count passing perforations formed in the motor cooling fan. Therotation of the motor may also be tracked by monitoring the electricalleads to the motor. In particular, the movement of the brushes fromplate to plate on the commutator generates noise on the motor leadswhich can be detected to measure motor rotation.

When security mode is implemented on tools without a rotary chuck orequivalent structure for manually inputting a passcode, a rotary dial,such as the previously described dial 470 with indicia 472 may be usedto enter this code. Even a single button could be used to detect apredetermined pattern of actuation, similar to Morse code. Also, thesequence and/or number of times at which at least two buttons aresequentially pressed may be used to input the passcode. As yet anotheralternative, the user may sequentially actuate the trigger for adetermined sequence of time periods, which define passcode. In thisconfiguration, the tool may emit periodic beeps or other audible orvisual signals to enable the user to measure the passing of time. By wayof example, a user's passcode may be sequentially actuate the trigger,or other user input, for periods of five beeps, then seven beeps, thenthree beeps. These configurations are particularly useful when the tool(for example, a saw or sander) does not include a rotatable chuck thatmay be used to scroll between sequences of indicia. In any case, thecombination or password associated with the tool would typically beincluded with the tool at the time of purchase, just like thecombination for a combination lock. An advantage of the above-describeddisplay is that it is possible for a user to select that user'spersonalized code.

Instead of requiring the user to manually enter the user's passcode, thepasscode may be transmitted to the controller via proximity or contactwith a security station that is normally maintained separate from thetool. An example of such a station is schematically illustrated in FIG.27 at 570. For example, station 570 may be housed within the charger forbattery 54, or retained on a key fob (much like the remote controllerfor a vehicle's alarm), or incorporated into another handheld unit.Station 570 is programmed to transmit a passcode to controller 26, whichin this embodiment includes a receiver adapted to receive the passcodefrom the station. For example, the station may transmit the passcodethrough a direct linkage 572 to the controller, such as through a patchcord, or socket that connects the station to the controller.Alternatively, the station may transmit this code via any suitablemethod of wireless communication, such as those discussed above withrespect to FIG. 5, and indicated generally in FIG. 27 at 574. Station570 may be used with any of the embodiments of the tool describedherein, including other portable tools in which the security mode may beimplemented, such as portable saws and air compressors.

An advantage of using such a station for actuating the security mode isthat it removes the requirement that the owner of the tool remember thepasscode required to actuate and deactivate the security code. It alsoremoves the concern that someone other than the owner or authorized userof the tool will learn the passcode and thereby be able to steal andcontinue to use the tool. Instead, the owner simply needs to retain thestation in a safe location, such as at the owner's house, on the owner'skey chain, in the tool crib where the tools are stored after use, etc.Because the station will not be retained with the tool when the tool isin use, theft of the tool will render the tool inoperable after a periodof time and the thief will lack the station, which is preferablyspecific to a particular tool, required to deactivate the security modeand render the tool operable again. Also because the passcode is notreadily apparent, even with possession of the station, a tool and itscorresponding station may be loaned to others without the owner worryingabout someone else learning the owner's passcode.

As shown in FIG. 22, the switches and dials are recessed within body 462and selectively enclosed by a cover 476. Cover 476 preventsunintentional operation of and protects the switches and/or dials, suchas when the tool is in operation. However, the switches may be usedwithout a cover and/or without being recessed within the housing.

An alternative user interface shown in FIG. 23 and includes a smalldisplay 490 and user input buttons 492 and 494. Display 490 ispreferably small enough to be located in a recess 496 located in thehousing of a tool and covered by a hatch 498. In the case of a smalldisplay, the buttons would typically be used to step through the variousavailable modes, such as by pushing both buttons simultaneously. Oncethe selected mode or parameter was displayed, the individual buttons, orthe chuck or trigger, can be used to select a particular value or turn afeature on or off. Display 490 has the advantage of being smaller andtherefore more economical. In addition, because of its small size, it isrelatively easy to protect against damage, such as by hatch 498.

In the Figures discussed above, Applicants' hand tool has beenillustrated as an electrically powered drill. It should be understoodthat Applicants' invention is not limited to drills, and appropriateaspects of the invention may be embodied in any other type ofelectrically powered hand tools, such as a portable miter or chop saw,or an air compressor. As illustrative, non-limiting examples, thesecurity feature may be used in virtually any powered hand tool.Similarly, user-interface 40 (and 40′), battery cord 102 and powersupply 118 may be used with any battery-operated hand tool.

As discussed above, the controller may be located in various positionsrelative to the tool. For example, it may be positioned anywhere withinthe housing of the tool, such as within the body or handle, or it may beat least partially separate or separable from the housing of the tool.Another embodiment of the controller is shown in FIGS. 24 and 25. InFIGS. 24 and 25, controller 26 forms part of a modular control assembly,which is generally indicated at 500. Examples of known modular controlassemblies are disclosed in U.S. Pat. No. 5,798,584, the disclosure ofwhich is hereby incorporated by reference.

As shown in FIG. 24, control assembly 500 is housed within handle 16,and includes a housing 502 and an actuator, namely trigger 50. As shown,trigger 50 is slidable between a range of positions between anunactuated position (shown in dashed lines) and a fully actuatedposition (shown in solid lines). It should be understood that asolid-state trigger may be used as well, as previously described herein.Controller 26 and various sensors, switches and other electronics arehoused within housing 502. Having the controller and its relatedsensors, wiring, switches, etc. contained within a discrete modularhousing offers the advantage that these components may be more easilyprotected from damage and contact with dirt, water and othercontaminants, as well as facilitating easy assembly. Housing 502 may bewaterproof to further protect the control assembly from exposure towater and other liquids, which also enables the tool to be used in wetenvironments. Furthermore, control assembly 500 may be easily removedand replaced as a unit, without requiring significant disassembly of thetool and without requiring extensive testing to determine what elementor subelement of the tool's mechanical and/or electronic system ismalfunctioning.

As shown in FIG. 25, control assembly 500 includes an input 506 throughwhich electrical power is delivered from power source 24, such asbattery 54, and an output 508 through which the electrical power isdelivered to motor 20. Control assembly 500 further includes a reversingswitch/electric brake 510, current sensor 512 and a power switch(typically a MOS-FET transistor) 514. Control assembly 500 may alsoinclude a high-speed electromechanical bypass 516 operated by depressionof trigger 50 to its fully actuated position. Responsive to a signalfrom trigger 50 and a signal from current sensor 512, controller 26regulates the flow of electrical power from power source 24 to motor 20via power switch 514. Reversing switch 510 controls the direction inwhich motor 20 rotates. The contacts of switch 510 may also be adaptedto brake the motor when power is not being supplied, such as by shortingthe contacts to the motor. Control assembly 500 may communicate withother sensors external housing 502, such as the previously describeddepth and position sensors.

In addition to the components described immediately above, controlassembly 500 may include many of the features and modes of operationdescribed previously. For example, control assembly 500 may include afurther input 518 through which a user interface may communicate withcontroller 26, such as via a wireless transmitter or patch cord, aspreviously described with respect to FIG. 5.

A non-limiting example of one of the previously described modes ofoperation/features that may be implemented and controlled by controlassembly 500 is security. The user's passcode may be entered via a userinterface, or may be entered via trigger 50. For example, as shown inFIG. 24, trigger 50 includes a position indicator 520, and housinghandle 16, or another suitable portion of body 12, assembly 500 orhousing 502, includes a series of spaced-apart indicia 522, such asnumbers, letters, or other symbols, which may be sequentially selectedby the user to enter the user's passcode. As shown, indicia 522 includenumbers, and by aligning indicator 520 with a selected number orsequence of numbers, the user may enter a passcode to the controller.When operating in security mode, the controller is preprogrammed tocorrelate the signal it receives to indicate the relative position oftrigger 50, with a stored sequence of positions representative of theuser's passcode. For example, from position 0, the user's passcode maybe to slide the trigger to 5, 2, 4 then 1. Of course, any number ofvalues may be used in the passcode, and the user may need to return thetrigger to position 0 between selected numbers to signal the controllerbetween selected numbers. The previously described audible and othermethods of using trigger 50 to enter a passcode may also be used. Amicroswitch, such as previously described switch 478 may also beincluded with control assembly 500 to enable the user to enter apasscode via the settings of switches 480.

Control assembly 500 may also include one or more additional switches,dials or other inputs, such as microswitch 524, to allow the user toselectively control the configuration and mode of operation of the tool,as described previously with respect to FIG. 22 to implement such modesof operation as tap mode, step mode, torque mode, trigger mode and pushmode. For example, switch 524 may extend through handle 16, orpreferably is recessed within handle 16 and covered by a cover that maybe selectively opened by the user when the user desired to manipulatethe switch and/or any other dials and controls protected by the cover.

By turning back to FIG. 28, several other features of the invention areshown on a tool 610. It should be understood that any of the featuresshown in FIG. 27 may be incorporated into a tool individually, together,or in combination with one or more of the other features disclosedherein. The features in FIG. 27 are being illustrated together forpurposes of brevity.

Besides the previously discussed security indicia 562, security station570, and waterproof battery connection 590, tool 610 also includes achuck 612 that is at least substantially housed within the body 614 ofthe tool. Unlike conventional keyless chucks, such as shown in FIG. 1,which are manually opened and closed about a bit and which extend atleast substantially in front of the body of the tool, chuck 612 is atleast substantially housed within body 614. As such, chuck 612 isshielded from being damaged and also is prevented from damaging objectswhen the tool is used. Conventional exposed chucks may scratch orotherwise damage adjacent objects if those objects are contacted by therotating chuck. Also, because the chuck is housed within body 614, itdoes not require the external shell required on exposed chucks, therebymaking it less expensive to manufacture. To provide the user withadditional gripping surface area for manually operating the chuck, theexternal shell is also generally larger then required simply to housethe mechanical components of a chuck. In the embodiment of the presentinvention utilizing an internal chuck, this larger shell is unnecessaryand can be eliminated, thereby making the operating end of the drillmore compact.

Chuck 612 includes an internal control ring (not shown) that rotatesrelative to the chuck to open or close the jaws of the chuck. Details ofsuitable construction for a such a chuck are shown in U.S. Pat. No.5,452,906, which is incorporated herein by reference. The internalcontrol ring would correspond to split nut 38, shown FIG. 2 of thatpatent, and possibly a small shell to retain the halves of the splitnut. However, the shell can be relatively small since it does not haveto be large enough to be comfortably operated by a users hand. A chuckhold device 154, such as disclosed with respect to the drill shown inFIGS. 8-10, is used to selectively prevent the control ring fromrotating with the chuck. Chuck hold 154 includes an actuator 616, suchas a button or switch on the body of the tool. Two illustrative examplesof suitable positions for actuator 616 are shown in FIG. 27, however, itis within the scope of the invention that other positions and forms ofactuators may be used. When the actuator is pressed, a member engagesthe control ring to prevent further rotation relative to the housing.With the control ring fixed relative to the housing, any operation ofthe motor drives the jaws of the chuck in or out. Thus, the user usesthe trigger and forward and reverse switch to control opening andclosing of the jaws of the chuck. Another advantage of this system isthat the user can press the actuator and trigger with one hand tothereby allow one-handed loading or unloading of the chuck. This freesthe other hand to stabilize the tool being engaged by the chuck.

An example of a chuck 810 with an internal control ring 812 isillustrated in FIG. 34. Chuck 810 fits into a drill housing 813 andincludes jaws 814 spaced around the axis of the chuck. Each jaw includesa threaded region 816 on its surface. The threaded region is preferablyvery fine, i.e. greater than twenty threads per inch, to provide goodmechanical advantage when closing the jaws, although it is within thescope of the invention that the number of threads per inch may begreater or fewer than the example given above. The jaws are slideablyreceived into bores, such as bore 818, formed in chuck body 820. Thechuck body includes a socket 822 at the back to engage the output of thedrill's gearbox. The outer end of the chuck may be supported in thehousing by a set of bearings 824. The bearings run in a groove, or race,826 formed in the outer surface of the body and are held at spaced-apartintervals by a bearing guide 828. Depending on the rigidity of thevarious components of the drill, it may or may not be necessary toprovide this support. Furthermore, as described below, the housing neednot extend to the end of the chuck.

Control ring 812 includes a pair of split nuts 830 that fit around thechuck body and include female threads 832 to engage threaded region 816on jaws 814. The control ring also includes a retainer band 834 that ispress fit, or otherwise suitably retained, around the split nuts to holdthem together. The retainer band includes a plurality of circumferentialholes 836 to engage a button actuator 838. When the button actuator ispushed, it fits into one of the holes and prevents the control ring fromrotating with the chuck relative to the drill housing. When the motor isoperated to rotate the chuck in this configuration, the rotation of thecontrol ring over the jaws drives the jaws open or closed depending onthe direction of rotation. It should be understood that any othersuitable mechanism may be used for selectively preventing rotation ofthe control ring with the chuck. Examples of other suitable mechanismsare disclosed herein with respect to the drill shown in FIGS. 8-10.

An alternative embodiment of this chuck is shown in FIG. 35. In FIG. 35,the external surface of the retainer band is serrated like the teeth ofa gear. A portion of the opposing internal surface of the housing issimilarly serrated. The actuator, such as shown at 616, is operativelycoupled to a pushrod 842. When actuator 616 is acted upon by the user,it drives a cam 840, via pushrod 842, into the region between thehousing and the control ring. The cam includes externally serratedsurfaces that engage the corresponding surfaces of the housing and thecontrol ring to prevent the control ring from rotating relative to thehousing. The actuator is preferably elastically biased to withdraw thecam when the user releases the actuator, thereby freeing the controlring to rotate with the chuck. It should be noted that while the drillhousing is shown terminating near the control ring in this embodiment,it could extend partially or all the way to the end of the chuck.Moreover, provided that some mechanism is provided to engage the controlring, it is not required that the housing cover any portion of thechuck. It may be desirable to limit the torque applied to the chuckduring use of the internal control ring to prevent damage to the chuckif too much torque is available. This can be accomplished by providing aswitch operated by the actuator to signal the controller to limit motorcurrent and thereby torque.

As another variation shown in FIG. 36, the control ring can be providedwith a partially telescoping shell 844. An exterior portion of the shellis provided with serrations that engage corresponding structure formedon the front of the housing. By sliding the shell back against thehousing, torque from the housing is transferred to the shell to preventthe control ring from rotating. The shell is preferably spring biased toreturn to the disengaged position when released by the user. Similarly,the forward portion of the housing can be provided with a portion thatcan be extended selectively engage a portion of the rear surface of thecontrol ring, even where the housing does not envelope any portion ofthe chuck. The engagement between the shell/control ring and the housingcan take the form of a frictional connection, teeth which are sloped totransfer a given amount of torque proportional to the pressure exertedbetween the shell/control ring and the housing, or an interlockingconnection, where the shell/control ring is locked to the housingindependent of pressure applied. Square castellations or teeth on therear face of the shell/control ring and forward face of the housingcould be used to provide an interlocking connection. Alternatively, thehousing could telescope over an irregularly shaped portion at the rearperimeter of the shell/control ring to provide an interlockedconnection.

It should be noted that the internal chuck design is also particularlysuitable for use with the previously described palm drill configurationshown in FIGS. 8-10. As with the drill of FIG. 27, the housing of thepalm drill embodiments can be extended forward to envelope the chuck. Asdescribed above, this arrangement can be used to reduce the profile ofthe drill because the user operable rings or shells on the chuck are nolonger necessary. These embodiments of chuck may also be incorporatedinto right angle drills.

When a shielded chuck 612 is used, it may also be desirable to locate atleast one of the previously described position sensors 42 near theleading edge of the body, which in this embodiment is also proximate theleading edge of the chuck. In this position, the sensor will be muchcloser to the axis of rotation and thereby much less susceptible toparallax errors in measuring distance as can occur with a single sensorpositioned off-axis measuring to an angled surface. This allows moreaccurate measurement of distance without requiring multiple sensors toaccount for tipping of the drill relative to the work surface.

When the tool shown in FIGS. 8-10 was discussed, it was also discussedthat the force transducer 219 disclosed in those figures may beincorporated with any of the other embodiments of the invented tooldisclosed herein. An example of such a transducer 219 used with tool 610is shown in FIG. 27, in which the transducer is positioned between thetool's motor 20 and gear box assembly 618, with the gear box assemblyaxially slidable but rotationally fixed with respect to the motor. Asshown, the output shaft 620 of the motor extending through a passage inthe transducer. When the user applies force to the drill along the axisof the chuck, this force is transmitted through gear box assembly 618 totransducer 219, which communicates this force to the controller 26 (notshown).

As discussed with respect to FIGS. 1 and 4, the handle and/or thebattery may be detached from the body of the tool while remaining inelectrical communication therewith to permit operation of the toolwithout having to support the entire weight of the tool in one hand.When the tool is used in this configuration, it may also be desirable tobe able to selectively stow the tool when not being used. In FIG. 27, aretainer is shown on the body of the tool and generally indicated at622. There may also be a similar retainer on the opposite side of thehousing. Retainer may be any suitable device for removably securing thetool to the user's belt, clothing, etc. Examples of suitable retainersare clips, such as shown with respect to battery 54 in FIG. 4, and hookand loop fasteners. It should be remembered that with the significantweight of the battery separated from the body of the tool, the remainingportion of the tool is relatively lightweight. Therefore, retainers thatpreviously could not support the weight of a tool and its battery maynow be used.

In FIG. 27, it can also be seen that the trigger differs from thetrigger shown in FIGS. 1 and 4. In FIG. 27, the trigger is generallyindicated at 630. Trigger 630 actually includes a pair of triggers 632and 634. As shown, the lower trigger 634, referred to herein as asecondary trigger, includes a portion 636 that is nested with primarytrigger 632 so that actuation of primary trigger 632 will also actuatethe secondary trigger. However, the secondary trigger may also beactuated independent of the primary trigger. When the triggers arenested together, as described above, actuation of the secondary triggeralong with the primary trigger produces the same result as if only theprimary trigger was actuated. The nesting, or interlocking, describedabove enables the user to not have to precisely position the user'sfinger to actuate only the primary trigger. Precise placement is onlyrequired for the secondary, less-frequently used, trigger. It is withinthe scope of the present invention that both triggers may be separatelyactuated independent of each other, and that actuation of both triggerssimultaneously could signal the controller to actuate a third feature ormode of operation separate from the mode for which the first and secondtriggers are configured.

Having dual triggers enables two of the above-described modes ofoperation to be configured and selectively used without having toreconfigure the tool. For example, the primary trigger may be configuredto function like a conventional trigger on a drill, while the secondarytrigger may be configured to actuate one of the versions of step modedescribed herein. Other combinations include one trigger controllingspeed and the other controlling torque, one configured to control speed,torque, or the step and the other configured for tap mode, and bothtriggers configured for different step modes. Furthermore, the primarytrigger could control forward rotation, while the other trigger controlsreverse.

While the invention has been disclosed in its preferred form, thespecific embodiments thereof as disclosed and illustrated herein are notto be considered in a limiting sense as numerous variations arepossible. Applicants regard the subject matter of the invention toinclude all novel and non-obvious combinations and subcombinations ofthe various elements, features, functions and/or properties disclosedherein. No single feature, function, element or property of thedisclosed embodiments is essential to all embodiments of the invention.The following claims define certain combinations and subcombinationswhich are regarded as novel and non-obvious. Other combinations andsubcombinations of features, functions, elements and/or properties maybe claimed through amendment of the present claims or presentation ofnew claims in this or a related application. Such claims, whether theyare different, broader, narrower or equal in scope to the originalclaims, are also regarded as included within the subject matter ofapplicants' invention.

1. An electrically powered hand drill/driver, comprising: a rotatablework element adapted to receive a bit; a motor adapted to drive therotation of the work element during powered operation of thedrill/driver; a body having a housing containing at least the motor anda handle adapted to be gripped by a user while operating thedrill/driver; a power source adapted to deliver power to the motor; atleast one user input; wherein the at least one user input includes anactuator adapted to be depressed by a user to select powered operationof the drill/driver; at least one distance sensor adapted to measure adistance from the distance sensor to a workpiece; and a controllerelectrically connected to the at least one distance sensor, whereinresponsive to the distance, the controller is adapted to at least one ofcontrol the delivery of power to the motor from the power source andactuate a feedback mechanism.
 2. An electrically powered hand tool,comprising: a housing; a work element extending from the housing andadapted to receive a bit; a motor adapted to drive rotation of the workelement during powered operation of the tool; a power source adapted todeliver power to the motor; a distance sensor adapted to emit and detecta distance-measuring signal; a user interface adapted to receive auser-selected value corresponding to a desired setting; and a controlleradapted to receive a signal from the distance sensor and determinetherefrom a measured distance from a reference position on the tool to aworkpiece, wherein the controller is further adapted to determine whenthe desired setting is achieved by comparing the measured distance tothe user-selected value.
 3. The electrically powered hand tool of claim2, wherein the desired setting is a desired distance between a referenceposition associated with the tool and the workpiece.
 4. The electricallypowered hand tool of claim 3, wherein the desired distance correspondsto one of a distance to which the bit is inserted into the workpiece anda distance a screw rotated by the bit is inserted into the workpiece. 5.The electrically powered hand tool of claim 3, wherein the desireddistance corresponds to a relative distance measured from a referencedistance between the distance sensor and the workpiece before poweredoperation of the hand tool is initiated.
 6. The electrically poweredhand tool of claim 5, wherein the controller is further adapted todetermine a change in the relative distance, and further wherein thedesired distance is achieved when the change in the relative distance isequal to the desired distance.
 7. The electrically powered hand tool ofclaim 3, wherein the controller is further adapted to interrupt deliveryof power to the motor when the desired distance is achieved.
 8. Theelectrically powered hand tool of claim 3, wherein the controller isfurther adapted to at least one of apply a reverse torque to the workelement when the desired distance is achieved and electrically brake thework element when the desired distance is achieved.
 9. The electricallypowered hand tool of claim 3, wherein the controller is further adaptedto actuate a feedback mechanism after commencement of a poweredoperation of the tool and prior to the desired distance being achieved.10. The electrically powered hand tool of claim 9, wherein the feedbackmechanism includes at least one of an audible signal, a visual signal,and reducing the delivery of power to the motor.
 11. The electricallypowered hand tool of claim 3, further comprising a plurality of distancesensors, each distance sensor adapted to emit and detect adistance-measuring signal; wherein the controller is adapted to receivea signal from each of the distance sensors and determine from thesignals a measured distance from a reference position on the tool to theworkpiece.
 12. The electrically powered hand tool of claim 2, whereinthe desired setting is a desired angular orientation of the toolrelative to the workpiece; wherein the tool further comprises aplurality of distance sensors, each distance sensor adapted to emit anddetect a distance-measuring signal; and further wherein the controlleris adapted to receive a signal from each of the distance sensors anddetermine from the signals an actual angular orientation of the toolwith respect to the workpiece.
 13. The electrically powered hand tool ofclaim 12, wherein the controller is adapted to determined the actualangular orientation of the tool with respect to the workpiece regardlessof the angular orientation of the tool relative to a ground surface, atrue vertical position, and a true horizontal position.
 14. Theelectrically powered hand tool of claim 12, wherein the controller isfurther adapted to prevent powered operation of the tool when the actualangular orientation does not equal the desired angular orientation andto permit powered operation of the tool when the actual angularorientation is equal to the desired angular orientation.
 15. Theelectrically powered hand tool of claim 12, wherein the controller isfurther adapted to determine if the actual angular orientation is withina predetermined tolerance of the desired angular orientation.
 16. Theelectrically powered hand tool of claim 15, wherein the controller isfurther adapted to prevent powered operation of the tool when the actualangular orientation is not within the predetermined tolerance of thedesired angular orientation and to permit powered operation of the toolwhen the actual angular orientation is within the predeterminedtolerance of the desired angular orientation.
 17. The electricallypowered hand tool of claim 12, wherein the controller is further adaptedto actuate a feedback mechanism to guide a user to position the tool inthe desired angular orientation.
 18. The electrically powered hand toolof claim 17, wherein the controller is adapted to actuate the feedbackmechanism when the actual angular orientation equals the desired angularorientation.
 19. An electrically powered hand tool, comprising: ahousing; a work element extending from the housing and adapted toreceive a bit; a motor adapted to drive rotation of the work elementduring powered operation of the tool; a power source adapted to deliverpower to the motor; a plurality of distance sensors, each distancesensor adapted to emit and detect a distance-measuring signal; and acontroller adapted to receive a signal from the plurality of distancesensors and determine therefrom an angular orientation of the tool withrespect to the workpiece; and further wherein the controller is adaptedto at least one of (1) restrict powered operation of the tool when theangular orientation is not within a predetermined tolerance of apredetermined angular orientation, (2) indicate the angular orientationto a user via a display on a user interface; and (3) indicate to theuser via a visual or audio feedback mechanism when the angularorientation is within a predetermined tolerance of the predeterminedangular orientation.
 20. The electrically powered hand tool of claim 19,further comprising a user interface adapted to receive a user inputselecting at least one of the predetermined angular orientation and thepredetermined tolerance.